Fixes issue #21 (compilation error in debug mode).

Author: prj-

examples++-load/Element_Mixte3d.cpp

@@ -2274,8 +2274,8 @@ namespace Fem2D {
 	const GQuadratureFormular<R3> TypeOfFE_RT1_3d::QFtetra(QuadratureFormular_Tet_2);
 
 	TypeOfFE_RT1_3d::TypeOfFE_RT1_3d (): GTypeOfFE<Mesh3>(dfon, d, 1, 3 * QFface.n * 3 * Element::nf + 3 * QFtetra.n * 3 * 3, Element::nf *QFface.n + QFtetra.n, false, true) {
-		assert(QFe.n);
-		assert(QFf.n);
+		assert(QFface.n);
+		assert(QFtetra.n);
 		// 4 ref tetra vertices
 		R3 Pt [] = {R3(0., 0., 0.), R3(1., 0., 0.), R3(0., 1., 0.), R3(0., 0., 1.)};