Checker --------------- 09.06.08 Checker2008v1a released. 14.06.08 Checker2008v1b released. Some minor flaws in parse errors reporting are corrected. 09.08.08 Checker2008v1c released. It has slightly modified syntax, modus ponens rule for WUSO (second order) formulas, and was coded using new parser generator Maphoon (by Hans de Nivelle).