Report problems with CAS and its interface.

[parisse]

subst does not quote it's arguments, therefore if a is assigned say to 2
subst(a*x^2+b*x+c,[a = -6,b = -4,c = 2])
will eval a*x^2+b*x+c to 2*x^2+b*x+c, as well as a=-6 to 2=-6, and a will not be replaced by -6.
A warning is displayed in the terminal.