Procedure factor begin if sym=ident then getsym e⊥se if sym=number then getsym e⊥se if sym=( then begin getsym expr i 1f sym- then getsym else error end else error end 1212 Procedure factor; begin if sym=ident then getsym else if sym=number then getsym else if sym= ‘ ( ‘ then begin getsym; expr; if sym= ‘ ) ’ then getsym else error end else error end; –