(1) -> )lib AXIOM SINF SYMCAT SYMB AND SEXPR

   >> System error:
   The value
  598
is not of type
  LIST

Just identities for addition and multiplication (required for pattern matching)

MYSYM:=Symbolic(Integer,ID)

   There are no library operations named Symbolic 
      Use HyperDoc Browse or issue
                              )what op Symbolic
      to learn if there is any operation containing " Symbolic " in its
      name.

   Cannot find a definition or applicable library operation named 
      Symbolic with argument type(s) 
                                    Type
                                Variable(ID)

      Perhaps you should use "@" to indicate the required return type, 
      or "$" to specify which version of the function you need.

x:=1+2+3

(1)

simplify x

(2)

simplify(x+y)

(3)

r1:=_rule(2,4)$RewriteRule(Integer,Integer,MYSYM)

   MYSYM is not a valid type.