def shrink

bend-collections-laws-math@1.0.0.0 · proofs/math/natural/roots.bend:148

import Base
import bend-collections-laws-math@1.0.0.0/proofs/lib/nat.bend as N

148# the interval shrinks: a step fits in the remaining fuel
149def shrink(+x: Nat, +y: Nat, +f: Nat, +h: {Nat.is_lt(x, y) == True{} : Bool}, +hf: {Nat.is_le(y, 1n+f) == True{} : Bool}) -> {Nat.is_le(x, f) == True{} : Bool}:
150  N.lt_succ_le(x, f, N.lt_le_trans(x, y, 1n+f, h, hf))