I looked around and didn't see this question on the forum, so my apologies in advance in case this has been answered here.
My question can be concisely described by the following example:
a = b + c; x = a + b + 2 c
The output for "x" will never contain "a", but will substitute "b+c" instead - which is obvious given my assignment of "a". How do I output "x" in terms of "a"?
Is there a built-in function that allows me to output "x" in terms of "a", or should I assign a relation for "a" differently?
My apologies for the simplicity of the question (might sound stupid to many).
Thanks a lot in advance for any help!