?-
project(suppliers,[sno],t41),
project(parts,[pno],t42),
project(projects,[jno],t43),
times(t41,t42,t44),
times(t44,t43,t45),
project(spj,[sno,pno,jno],t46),
minus(t45,t46,t47),
project(t47,[sno,pno],t48),
project(suppliers,[sno],t49),
project(parts,[pno],t410),
times(t49,t410,t411),
minus(t411,t48,t412),
project(t412,[sno],t413),
displayRelation(t413).