def Fin.bound
import bendtorch-core@0.1.0.0/src/shape/core.bend as Coreimport Base
45def Fin.bound(+n: Nat, +index: Fin(n)) -> LT(Fin.value(n, index), n):
46 match n:
47 case 0n:
48 match index:
49 case 1n+k:
50 match index:
51 case FZero{}:
52 Unit{}
53 case FNext{+previous}:
54 Fin.bound(k, previous)