@pachydermic you can use math.parse("abx + c = y") which returns an expression tree. You can perform transformations on this tree. See docs: http://mathjs.org/docs/expressions/expression_trees.html. There is an early implementation of algebraic differentiation (not yet public): https://github.com/josdejong/mathjs/pull/411. Next step is to implement functions simplify and integrate. It all looks very promising.