module Slp {
pos = (string? file,int line, int offset)

stm = Compound(stm head,stm next)
    | Assign(identifier id,exp exp) 
    | Print(exp*)
     attributes (pos p)

real = (int mantissa, int exp)
exp = Id(identifier id)
    | Num(int v)
    | Op(exp lexp,binop bop,exp rexp)
     attributes (real? value)	

binop = Plus | Minus | Times | Div

}
