tcfail042.hs:16: Context `{PrelBase.Num taHz}'
		     required by inferred type, but missing on a type signature
		     `PrelBase.Num taHz' arising from an instance declaration at tcfail042.hs:16
    When checking superclass constraints of an instance declaration
 
tcfail042.hs:4: Module Main must include a definition for `Main.main'


Compilation had errors