String processing in Maxima

Question

I am new to Maxima.

I've read the manual and I couldn't find a function to identify whether a certain variable is present in a string or not.

Note: I am trying to create a function that allows me to mimic the Maxima function augcoefmatrix().

Answer 1

I don't know what you're trying to do, but string operations on stringified expressions is almost certainly the wrong way to go about it. What, exactly, is your goal here?