Is there a way to insert comments at the end of a line, within a block of TeX? For example, something like the following
$$\begin{align}
&(B \cap A) = (C \cap A) \\ 'given
&(B \cap A) \cup (B \cap \overline{A}) = (C \cap A) \cup (C \cap \overline{A}) \\ 'substitution and distributive law \end{align}$$
&B = C
where ' would indicate a comment. It would be handy for justifying certain steps when writing proofs.
alignenvironment? – Werner Oct 01 '13 at 04:19\[…\]preferable to$$? – Werner Oct 01 '13 at 04:20