Index: /issm/trunk-jpl/src/c/classes/Elements/Penta.cpp
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Penta.cpp	(revision 15846)
+++ /issm/trunk-jpl/src/c/classes/Elements/Penta.cpp	(revision 15847)
@@ -9746,5 +9746,5 @@
 	/*Viscosity*/
 	viscosity = 1./(2.*A*(tau_par*tau_par + tau_perp*tau_perp));
-	//_assert_(!isnan(viscosity)); this is not defined for adoubles
+	_assert_(!xIsNan(viscosity));
 	_assert_(viscosity > 0.);