# type(a, data type) test if a is data type;
# type(a) return a data type;

type(a_,number):=isnumber(a);
type(a_,complex):=iscomplex(a);
type(a_,integer):=isinteger(a);
type(a_,float):=isfloat(a);
type(a_,function):=isfunction(a);
type(a_,odd):=isodd(a);
type(a_,even):=iseven(a);
type(a_,constant):=isconstant(a);