a := vector(3): b := vector(3): c:=vector(3): n := crossprod(b-a,c-a); r := vector([x,y,z]): innerprod(n, r-a); collect(",[x,y,z]); P3points := proc(a,b,c) local ex1,ex2,n,_x,_y,_z,r; n := crossprod(b-a,c-a); r := vector([_x,_y,_z]); ex1 := innerprod(n,r-a); ex2 := collect(ex1,[_x,_y,_z]); ex2 = 0 end; P3points([0,0,-8],[0,4,0],[8,0,0]); readlib(isolate): isolate(P3points([0,0,-8],[0,4,0],[8,0,0]),- 256); "/32; isolate(",rhs(")); "*(-1); P3points([1,1,-2],[-1,1,0],[0,2,2]); "/(-8); "*4; isolate(",4); isolate(",rhs("));