tvh 2 'A' 'B' 'C' == [('A','C'),('A','B'),('C','B')]
tvh (-2) 'A' 'B' 'C' == []

erreichbarVon [[0,1,1,0],[1,0,0,1],[0,0,1,0],[0,0,0,0]] 2 == [1,2,3,4]
erreichbarVon [[0,1,1,0],[1,0,0,1],[0,0,1,0],[0,0,0,0]] 3 == [3]

istErreichbar [[0,1,1,0],[1,0,0,1],[0,0,1,0],[0,0,0,0]] 1 4 == True
istErreichbar [[0,1,1,0],[1,0,0,1],[0,0,1,0],[0,0,0,0]] 3 2 == False

palFrei "Ottos Lebensmotto" 5 == True
palFrei "Ottos Lebensmotto" 4 == Fals