consider g being Element of FuncsC X, C1, C2 being Element of CSp X such that
W: ( l = [[C1,C2],g] & ( union C2 = {} implies union C1 = {} ) & g is Function of (union C1),(union C2) & ( for x, y being set st {x,y} in C1 holds
{(g . x),(g . y)} in C2 ) ) by Th18;
[[C1,C2],g] `2 = g ;
hence ( l `2 is Function-like & l `2 is Relation-like ) by W; :: thesis: verum