Description: Define the evaluation map for the univariate polynomial algebra. The
function ( S evalSub1 R ) : V --> ( S ^m S ) makes sense when S
is a ring and R is a subring of S , and where V is the set
of polynomials in ( Poly1R ) . This function maps an element of
the formal polynomial algebra (with coefficients in R ) to a
function from assignments to the variable from S into an element of
S formed by evaluating the polynomial with the given assignment.
(Contributed by Mario Carneiro, 12-Jun-2015)