def strict_follow

stelliferous@0.0.2.0 · proofs/nat_order.bend:345

import Base
import stelliferous@0.0.2.0/proofs/word_encoding.bend as WordEncoding

345# Order structure shared by padding, allocation and mixed-radix indexing.
346def strict_follow(+a: Nat,+b: Nat,h: {Nat.is_lt(a,b) == True{} : Bool}) -> {Nat.is_le(1n+a,b) == True{} : Bool}:
347  match a b:
348    case 0n 0n:
349      Empty.absurd({False{} == True{} : Bool},WordEncoding.false_true(h))
350    case 0n 1n+b:
351      zero_le(b)
352    case 1n+a 0n:
353      Empty.absurd({False{} == True{} : Bool},WordEncoding.false_true(h))
354    case 1n+a 1n+b:
355      strict_follow(a,b,h)