convert "IXX" 1 2 == "XIX"
convert "XIX" 1 2 == "Ungueltige Eingabe"

codeCube "functionalprogrammingisfun" 7 == "fnriuaasnlmfcpmutrinionogg"
decodeCube "fnriuaasnlmfcpmutrinionogg" 7 == "functionalprogrammingisfun"

fragment ["Dieser Fliesstext","das Ausschneiden"] (1,1) 5 2 == ["Diese","das A"]
fragment ["Dieser Fliesstext","das Ausschneiden"] (1,1) 5 (-2) == []