View source for Schwarz symmetry theorem

If a [[Minimal surface|minimal surface]] passes through a straight line <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s083/s083590/s0835901.png" />, then <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s083/s083590/s0835902.png" /> is its axis of symmetry. This theorem implies that if the boundary of a minimal surface contains a segment of this line <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s083/s083590/s0835903.png" />, then this surface can be extended across this segment symmetrically with respect to <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s083/s083590/s0835904.png" />.