Is there a way to insert comments at the end of a line, within a block of TeX? For example, something like the following

&(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.