diff -r 783ef40344dd -r 182036ed6475 stage4/generate_c/generate_c_il.cc
--- a/stage4/generate_c/generate_c_il.cc	Tue Aug 20 11:15:40 2013 +0100
+++ b/stage4/generate_c/generate_c_il.cc	Wed Aug 21 16:06:43 2013 +0100
@@ -446,7 +446,7 @@
       symbol->accept(*this);
       s4o.print(",");
       if (negative) {
-	    if (get_datatype_info_c::is_BOOL_compatible(this->current_operand->datatype))
+        if (get_datatype_info_c::is_BOOL_compatible(this->current_operand->datatype))
           s4o.print("!");
         else
           s4o.print("~");