def walk_left_zero

bendtorch-core@0.1.0.0 · src/tensor/elementwise_walk_proof.bend:125

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape
import bendtorch-core@0.1.0.0/src/storage/arith.bend as Arith
import bendtorch-core@0.1.0.0/src/tensor/elementwise.bend as Elementwise

125# Rows whose left stride is 0 on every axis: every position walks to 0.
126def walk_left_zero(+rows: List<&2, Shape.Row>, +zero: {Elementwise.zero_left(rows) == True{} : Bool}, +i: Nat) ->
127  {Shape.walk_left(rows, i) == 0n : Nat}:
128  match rows:
129    case Shape.Row{+stride, +left, +right} <> +rest:
130      +none = Arith.eq_true(left, 0n, Arith.and_left(Nat.is_eq(left, 0n), Elementwise.zero_left(rest), zero))
131      %Equal.sym(Nat, left, 0n, none) : {Nat.add(Nat.mul(_, Nat.div(i, stride)), Shape.walk_left(rest, Nat.mod(i, stride))) == 0n : Nat}
132      walk_left_zero(rest, Arith.and_right(Nat.is_eq(left, 0n), Elementwise.zero_left(rest), zero), Nat.mod(i, stride))
133    case Nil{}:
134      {==}