-- | Determines if sig1 is subsignature of sig2
isSubSigOf :: Sign -> Sign -> Bool
isSubSigOf sig1 sig2 = Map.isSubmapOf (items sig1) $ items sig2
isSubSigOf :: Sign -> Sign -> Bool
isSubSigOf sig1 sig2 = Map.isSubmapOf (items sig1) $ items sig2
isSubSigOf sig1 sig2 = Map.isSubmapOf (items sig1) $ items sig2