src/builder.rs (4 lines):
	- line 181: // TODO: Tune epsilon as a function of the inputs. Numerical experiments?
	- line 210: // TODO: Tune epsilon as a function of the inputs. Numerical experiments?
	- line 247: // TODO: could be smarter here
	- line 281: // TODO: We want multiple calls to solve() to give a different


src/equation.rs (1 line):
	- line 46: // TODO: is_const? or maybe this gets the point across.