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█████ ██████████ ██ ██████ ███████████ █████ ███████, ██ ██████ ████ ████ █████████ ███ ███████ █ ████ ██ ██████ ██ ██████, █████ ███ ██████ █████ ███████ █████ ██ ███████.

██ █████████ ████████████ ███ ████████████ ██ █████ ███ █████ ██ █████ █████ ██████████ █ ██ ██████ ██ ███████, ████████ ████ ██ ████████ ███ ██ ███████ ██████ █████ ██ ███ ██████████ ███████████ ██ ██████ █ ███ █████████ ██████████████ ███ ██████:

${\displaystyle \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

██ ██ ██████ ██ ███████ █ █████ ██████ ██ ███, ██████ █ █████████ ███████████ ██ ██████ ████████. ██████████ ████ ██████████ ████████ ██ █████████████ ███ ███ ██████████ ██ ████ ██████████, ████████ ██ ██████ ████████ ███ ███, ██ █████ ████████ ███████████████ ██ █████████████ █████ ████████ ██████████ █ ██ ██████ ██████ █████ ██ █████████ ███ ███.

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████████ ██████████ ██ █████████████ ██████ ████ ███ ██████████ ███ ██████ ██ ████ ████████ ████████. ███ ███ ████ ███ █████ █████████ ███ ██████ ████████ █████ ██████ ███'███████ ██ ███ ██████ ██ ███████████ ██ ███████.

███████ ██ ██████ █████ ██ ███████ ██████████

████████ ██████████ ██ █████████████ ██████ ██ █████ ████████████████. █'███████████ ██ ██████ ███ █████ ████████████████ █ ████████ █████ █████████████████████.

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██ █████████ ██ █████████████ █████ █████, ███ ████ ██ ████ ██ ██ ██████, ███ ██████ ████████ ███ █████ ██ █████ ███████████ ██████████ ███:

██ ██████ ████ ██████, ██ ███████ ██████████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.}$

██████████ ██ ███████ ███ █████████ ██ ████████ ████ ███████ █ (█████ ███ █████ ██ ██████), █████████ █'█████████ ██ ██████████ ██ █████ ██ ██████████:

${\displaystyle \frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{\nabla }\cdot \left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███ ███ ██████ █████████ █████ ██ █████ █████████:

${\displaystyle \frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)}{\mathrm{\partial }{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███ ███ ██████ █████████ █████ ██ █████ ██████:

${\displaystyle \frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\right)}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\right)}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\right)}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

█ ██ ███████ █████ ████████ ██████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.}$

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██ ██████ █████████ ██ █████████████, ███ █████ ██ █████ █████████, ███ ██████ ████ ████████:

██ ████████ ██████ ██ █████ ███ █████ ██ ██████████, ███ █████ ██████████ ███ ██████ ██ █████ █ █ █ ██ ██ ██████, █ ███████████ ████ ██ ████████ ███ ██ ███████ █ ███ ██████, ██ ██████████ █████ ████████ ██ █████████ ██████████████ ████ ██████ ███████████ █ █'████ █████ ██████ ████████.

████████████ █'███████ ██ ████████ ████████████ ████████ ████████████ ██ ██████ ███ ██████ ███ █████ ████████ ██ ████ ██████ ███ ██ ███ ██████ █████ █ █████████ ██ ██████ ███ ██████ ██ ███ ██████ █ ███████ ███ ██████ ███████ █████ ██████ ██████████ ███████ ███ █████ ██ ██████ ████████ ██ █████ █████ ██ ██████████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

████ ███ █_█ █ █_█ ██ ████ ████████ ██ █████ ███████ (████ ██████████████) ████ █████████ █. ████████ █'█████████ ███ █████████, █████████ ██████████ ██ ██████████ ███ ██████, █████████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}-{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

██████████ ██ ████████████ ████ █████ █████████ ████████ █████████ ███ ██ ██████ █████ ████ ██████ █:

${\displaystyle \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\left(\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\left[\mathrm{\nabla }\cdot \left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\right]\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.}$

███████ ███ ██ ██████████ ██ █████ ███ █████ ██████ ███'███████ ███ ██████ █████:

${\displaystyle \frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=-\left[\mathrm{\nabla }\cdot \left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\right]\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

██ ██████, ███ █████ ██ ██████:

${\displaystyle \frac{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{\nabla }\cdot \left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███████████ █'███████████ ███████████████ ████████.

█████ ██ █████ ███████████

██ █████████████ █████ ████████ ██ ████ (████████ ████ ████████ █████ █████ ███ ██ ████████ █, ███ █████ ██ ██████, █████ ███████ ███ ██ ████████) ██ ███████ ██████████ ███:

█ ███████████████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

████, ███████, ███ █_█ ██ █ ████████ ██ █████ █████ █████ ███████, ██ █████ (████ ██ ███████ ██ █████ ██ ███████) █ ██ ██████████ (█████ ██ ███████ ██ █████ ███████).

████████████ ██████ ████████████████ █████ █████ ██ ███ ████████████ █████████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}={\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

██ █████ ██████ ███ ██████ ███████████ ██ █████ ███ ███████████ ████████ ██ ███████ ███ █████████ ██ ████████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}={\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\left(\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\left(\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\right)\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███ ███ ██████ ███████ █████ █████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}={\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\left(\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

████ █'██████ █████████ ████████ ███ █'█████████ ██ ██████████ ██ █ ██████ █████.

██ ██ ███████ ██ ███████ █████ ██████████ ███'██████ █████████ ████'█████████ █████ ████████ ██ ████, ████ █████████ █████████ ████ █████████ ██ ██████. █'█████████ ██ █████████ ██████ ████ █████:

${\displaystyle {\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>})}\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}-\mathrm{\nabla }\cdot \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\right)\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

████ ███ █ ██ █ ████████ ██ ███████ █████ ██████. ████ ███ █'███████████ ██████████ ████ ██████ ███ █████████ ██████████ ██████ ██ ████████████, █████ ██████ █████ █'██████████:

${\displaystyle \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\left(\frac{\mathrm{\partial }\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{\partial }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\left(\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\cdot \mathrm{\nabla }\right)\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{\nabla }\cdot \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███ ███████ █'█████████ █████ ████████ ██ ████ (███ █████ ██ ██████).

█████ ██ █████ █████████

██ ███████ █████████ █████ ████████ ███████ ██ █████████████ █████ ████████ ██ ████ █, ███ ██ ████████ ███ ██████ ███ ██████ █████████ ████ █████:

██████, ███ ████████████ █████████:

${\displaystyle \frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+{\oint }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\left(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\cdot \widehat{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}={\int }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+{\oint }_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

████ ██ ██████ (████ ██ ██████████ █ ███ ██ █████████) ███ █ ████████ ███ █████.

██ ███████ █████ ████████ ███ ██ ██████

██ ███████ █████ ████████ █ ███████ █████ ██████ █ ██ ███████ ███████████████ ██ ███████ █████, ██████████████ ██ ████ ██████████ █_██ ███ █████████████ ██ ███ ██████████ █████ ██████ █████ ███ █████████ ████████ ██ ██ █████ ███████ ██ ███████████ ██████████. ██ █████ ██████████:

██ ██ █████████ ███ ████████ ██████████, █████████ ███████ ██ ███████ █ ████ █████ ██████, █ ██ ██████████ █████ █████ ██████████ ███ ██ ████████ ██ ██████ ██ ██████████ █████ ██████ ████████ ██████████ ██ ██████ ██ ██████████ █████ ██████ ████████ ██ ██ ███ ██ ██████ ████████ ████ ██████████ █ ██ ██ ███████ █ █:

${\displaystyle {\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\frac{{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

██ ██████ █ ██████ ███ ██ █████ ███████ █████ ██████████ █ ████'████████████ █████ ██████████, ██████ ██ ██████ ███ ████ ████████████.

███ ████ ███████, ████ ██ ██ ██████ ██ ██████, █ ██████████ █████ █████████ ███ ██████, █'█████ █████ ████ █████████ ███████ █ ██ ██████ ██████████ ████ ████████ █████████. ██ ██ ██████ ██ ████ ██████, █'███████ ███ ██████ █████████ █ ███ ██ ███████ █ ██████████ ████████ ████ █████ █ █████ ██████████ ███████.

██ █████████ ███ ██████ ████████, ███ █ █████ ███ ██████ █████████ ██████████████ █████ ████████████ ███████ █████ ██████████, ███ █ ██████ ███ ██████ █████████ █████ ████████ ██ ████████████.

██████ ███ ███████████

███ ████ ██ ███ ██ ██████ ███ ███ ███████████, ████ ███ ███████ █████ ██████ ██████████, ██████ █_██ = █_██, ████████ ██ ████ ██████████ ████ ███████ █ ███ ████████ ████████████. ███ █ ██████ ██ █████ ███ █ ███████ █████████ ██████ █████ █████ ██ ██ █████ ██████ (███ ███████ ██ █████ ██ ███████████████ ██████████), ████████ ██ ██ █████ ████ (███ ███████ █), ███ █████ ███ ██ ██████ ███ ██████, ████:

${\displaystyle \left|{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right|={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{\prime }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}-{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{″}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\left(-\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{\prime }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\left(-\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right)-{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{″}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

██████ █'█████████ ███ ███████ █████████ ██ ██ ████ ███████ ██ ██ ██████████ ██ ██ ███████████████ █:

${\displaystyle \left|{\overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\right|={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

████ ███ █_█ ██ █ ████████ ██ ███████ █'███████ ███████ ███'████ █ █ ███ █_█ ██ ████████ ████████. ███████████ ██ ██████████ ███████████ ██ ███████:

${\displaystyle \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\frac{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\frac{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{\prime }+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{″}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}-\frac{{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{\prime }+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}^{″}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}.}$

██ ███████ ███ ██████ █ █, ██ █████████ █, █ █ █ ██████████ █ █, ██████ ███ ██████ █████ █████ ███████ ██████████ ██ ██ ██████ ██████. █████ ██████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}-{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}$

███ ████ █████ ███ ███ █████ ████.

█████████ ███ ██████ █ ████████ ██ ████████████: ██████ ██████████ ████████

██ ██████ ██ █████████ ██████████ ██████ ██ ███ █████████ ███ █████ ███ ██ ████████ █, ███ ██████ ██████, ██ █████████ ██████████ ███ ████ ██ ███████ █████ ██████ ████ ██████████ ███ ███████ █████ ████████ ██ ████████████ █ ███████.

███████████ ███████ ██ █████████ ███ ██████ ██████ █ ████████ ██ ████████████, ███████████ █ ████ ███ ████████ ███ ███ ████████ ███ ███████ (██████ ████ █████████ ███ ████████), █████████ ██ ████ ████████.

██ ████ ███ ████████ ██ ████████ ████ ██ ████ ███████: ████ ███ █████████ ███ ██████ ███████ █████████ ███████, ██████ ██ ███████ █████ ████████ ██ ████████████ (███ ███████████ ███ ${\displaystyle \underset{<span\; word-length="1"\; class="word\; redacted">█</span>}{\underset{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}}$) █ █████ ███ ███████. ██ ███████ ██████████:

████████████ ██████ ██ ██████ ██ ████, ████ ████, ███ ██ ███████████ ███████ ██ ███████████ ██████████, ███ ██████ █████ █████████ ███████ ████ █████████ ██ ██ ████████ ██ █████ ███████████████ (███████ ██ ███████████ █████ ████ ██████████ ██ ████████████). ███ ███████ ██████████ ███ ███:

███ ███████ ███ ███████ ██ ██████ ██████████ ██ ██ ██████, ████ ██████████ ███ ████ ██ ██████ ████████ (████ ██ ███████ █████ ██ ████) ██████ ██████████ (████ ██ ███████ ██ ██████, ██ ███ ████████ ████████████ ██ ██████ █████████ ███████ █████ ██████████ █████████). █'██████████ ██████ ████████ ███ █ ██████ ███ ███████████ █'████████████ █ █'████████████ ████ ██████ ██████████ ██ ████████, ██████████ █████ ██████ ██████████. ████████████ ██████ ██ ██████ ████████, ████ ████ █████ ██████ █_██ = █:

█████ ██████ ██ ███████████ ██ ████ ███ ████████, ████ ████ █████ ██ ██████████ █████ ██████ ███████ ███████ ██ ████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\ne \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\forall }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>};\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\Rightarrow {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\ne \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\forall }\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>};\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.}$

████ ██████████ ███ ███████ █████ ██████ ████ ███ █████ ████████, ███████ ███ ██████ ██████████, █████ ██████████ ███ ███████ █████ ████████ ██ ████████████. ███████████ ████ ████████ ██ █████ ██ ██████ (█████████ ██ █████ █████ ███ ██ ███ █████████ ██ █████████), ██ ███████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}({\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}).}$

█████ ███ ██ ████████ ████ ████████ ███████: █████████ ██ ████████ ██ ██ ███████ ██ ███████████ ███████████ █████ ██████ █████ ████ ██████████ ██ ████████████, ██ ██:

${\displaystyle \{\begin{array}{l}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}.\end{array}}$

███ █████ ████ ██████████ ████ ██████:

${\displaystyle {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.}$

█ █████ ███ █████ ███ ████████ ██ ██████ ██████████, ██ █ ███████ ████████ ███████████ ██ █████████████ ███ ██ ███ █████████ ██████████ ██ ████████████ █_█, █_█, █_█ █ ██████:

${\displaystyle \{\begin{array}{l}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\end{array}}$

█ ██████ ██ ███████ ████████ ██ █████ ████████ ████:

${\displaystyle \{\begin{array}{l}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}){\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\sum _{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}){\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\sum _{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}={\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+(\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}){\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\sum _{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}.\end{array}}$

██████, ███████ █████ ███

${\displaystyle \sum _{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}^{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}}$

█ ███████ ███ ████████

${\displaystyle \{\begin{array}{l}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\\ \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\end{array}}$

██ ███████:

${\displaystyle \{\begin{array}{l}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}=-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}=-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}=-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="2"\; class="word\; redacted">██</span>}}\end{array}}$

████ ██ ███████ ███████ ██ ███████ ██████ ████████ █'███████ █████ █████████ ██████ ████ ██████████ ██ ██████ ██ ███ ██████████ ██ ██████.

███ █████ ███ ███ █████████████ ██ ███████ ██ █████████ ██████████ ██ ████ ██ ███ █████ ██ ███████████ █████████:

${\displaystyle \{\begin{array}{l}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=-\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{\nabla }\cdot \overrightarrow{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}+\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\\ {\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}=\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}_{\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}}\mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}\ne \mathrm{<span\; word-length="1"\; class="word\; redacted">█</span>}.\end{array}}$

██ █████ █████████ ███ ███████ ██████████ █████████ ██ █████ ███, ███ ████ ████████, █ ███ ██████ ███████ ████ ██████████ ███ ████. ██ ████ █████ █:

████ ███ █' ██ █ ████████ ██ █████████ ██ ██████ (█ ██ ████████████ ████████████ ████ █████████), ██ █████ ████████ ██ ██████████ ███ ██ ██████ ███████ █████ █ ██ █████████ ██ ██ ██████, ██████ ████ █████████. ██ ██████ █████ █████████ ██ ██████ ██ ██████ █ ████████████ ███ █ ███, ██ ███████████ ███ ██████ ███████████.