Initial checkin of tribool library

[SVN r23452]

.gitmodules

@@ -186,6 +186,10 @@
 	path = libs/assign
 	url = ../assign.git
 	fetchRecurseSubmodules = on-demand
+[submodule "logic"]
+	path = libs/logic
+	url = ../logic.git
+	fetchRecurseSubmodules = on-demand
 [submodule "exception"]
 	path = libs/exception
 	url = ../exception.git

libs/logic

@@ -0,0 +1 @@
+Subproject commit e3146f2584c15ca4dbe542f5c561d96aa5723710