Index: /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/convert_to_RPN.c
===================================================================
--- /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/convert_to_RPN.c	(revision 40235)
+++ /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/convert_to_RPN.c	(revision 40236)
@@ -120,5 +120,4 @@
 	Nop_stack ++;
 	break;
-      case ST_UNARY: 
       case ST_BINARY: 
       case ST_TRINARY:
@@ -139,4 +138,5 @@
 	Nop_stack ++;
 	break;
+      case ST_UNARY: 
       case ST_LEFT:  
 	/* push operator on OP stack */
Index: /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/dvomath.c
===================================================================
--- /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/dvomath.c	(revision 40235)
+++ /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/dvomath.c	(revision 40236)
@@ -29,4 +29,8 @@
   unsigned int Ncstack;
   cstack = isolate_elements (argc, argv, &Ncstack); 
+
+  // for (i = 0; i < Ncstack; i++) {
+  //   fprintf (stderr, "%d : %s\n", i, cstack[i]);
+  // }
 
   /* generate RPN stack from cstack arguments */
Index: /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/evaluate_stack.c
===================================================================
--- /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/evaluate_stack.c	(revision 40235)
+++ /branches/eam_branches/ohana.20170822/src/opihi/lib.shell/evaluate_stack.c	(revision 40236)
@@ -110,5 +110,5 @@
 
 	if (i < 3) {  /* need two variables to operate on */
-	  snprintf (line, 512, "syntax error: trinary operator without three operands: %s\n", stack[i].name);
+	  snprintf (line, 512, "syntax error: trinary operator without three operands: %s\n(Note that the : in a trinary operation must be protected by spaces", stack[i].name);
 	  push_error (line);
 	  clear_stack (&tmp_stack);
@@ -124,5 +124,5 @@
 
 	/* there are no valid unary string operators */
-	snprintf (line, 512, "invalid operands for trinary operator %s (mismatch types?)", stack[i].name);
+	snprintf (line, 512, "invalid operands for trinary operator %s (mismatch types?)\n(Note that the : in a trinary operation must be protected by spaces)", stack[i].name);
 	push_error (line);
 	clear_stack (&tmp_stack);
@@ -131,5 +131,5 @@
       got_three_op:
 	if (!status) {
-	  snprintf (line, 512, "syntax error: invalid operand for trinary operation: %s or %s or %s\n", stack[i-1].name, stack[i-2].name, stack[i-3].name);
+	  snprintf (line, 512, "syntax error: invalid operand for trinary operation: %s or %s or %s\n(Note that the : in a trinary operation must be protected by spaces)", stack[i-1].name, stack[i-2].name, stack[i-3].name);
 	  push_error (line);
 	  clear_stack (&tmp_stack);