Math::Expr::Var - Represents a agebraic rule
reuire Math::Expr::Var; reuire Math::Expr; $r=new Math::Expr::Var($from, $to); @res=$r->Apply($expr)
This will create a rule that converts the expression $from to $to, and then apply that rule to $expr. $from, $to, $expr are all Math::Expr::Opp structures that should be Simplified to work ok. The result is a array @res of Math::Expr::Opp objects which should contain the results of applying the rule once on $expr in all possible ways. They are all simplified, and duplicaions are removed.
Makes a rule converting the Math::Expr::Opp structur $from into $to.