def AP.get_eq

bend-osdev-array@0.1.0.1 · PROOF.bend:623

import Base

623def AP.get_eq(-T: Data, t: AP.Tree<T>, n: U32, +i: U32, z: Bool) -> {Array.get.go(T, AP.build(T, t), n, i, z) == (AP.build(T, t), AP.get_v(T, t, n, i, z)) : Array<T> & T}:
624  match t z:
625    case APLeaf{x} _:
626      {==}
627    case APNode{xs, ys} True{}:
628      +h = U32.shr(n)
629      +z1 = U32.is_lt(i, U32.shr(h))
630      %Equal.sym(Array<T> & T, Array.get.go(T, AP.build(T, xs), h, i, z1), (AP.build(T, xs), AP.get_v(T, xs, h, i, z1)), AP.get_eq(T, xs, h, i, z1)) : {Array.swap.lo(T, AP.build(T, ys), _) == (ANode{AP.build(T, xs), AP.build(T, ys)}, AP.get_v(T, xs, h, i, z1)) : Array<T> & T}
631      {==}
632    case APNode{xs, ys} False{}:
633      +h = U32.shr(n)
634      +j = U32.sub(i, h)
635      +z1 = U32.is_lt(j, U32.shr(h))
636      %Equal.sym(Array<T> & T, Array.get.go(T, AP.build(T, ys), h, j, z1), (AP.build(T, ys), AP.get_v(T, ys, h, j, z1)), AP.get_eq(T, ys, h, j, z1)) : {Array.swap.hi(T, AP.build(T, xs), _) == (ANode{AP.build(T, xs), AP.build(T, ys)}, AP.get_v(T, ys, h, j, z1)) : Array<T> & T}
637      {==}