def eta_chain

bend-collections-laws-crypto@1.0.0.0 · proofs/math/typed/w64clz.bend:165

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/w64.bend as X

165def eta_chain(+x: U32) -> {X.bitlen(x) == X.bl_fin(S5(x)) : Nat}:
166  +e1 = {{==} : {X.bl_step(16n, (0n, x)) == S1(x) : Nat & U32}}
167  +e2 = Equal.trans(Nat & U32, X.bl_step(8n, X.bl_step(16n, (0n, x))), X.bl_step(8n, S1(x)), S2(x), Equal.cong(Nat & U32, Nat & U32, z => X.bl_step(8n, z), X.bl_step(16n, (0n, x)), S1(x), e1), eta_step(8n, S1(x)))
168  +e3 = Equal.trans(Nat & U32, X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x)))), X.bl_step(4n, S2(x)), S3(x), Equal.cong(Nat & U32, Nat & U32, z => X.bl_step(4n, z), X.bl_step(8n, X.bl_step(16n, (0n, x))), S2(x), e2), eta_step(4n, S2(x)))
169  +e4 = Equal.trans(Nat & U32, X.bl_step(2n, X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x))))), X.bl_step(2n, S3(x)), S4(x), Equal.cong(Nat & U32, Nat & U32, z => X.bl_step(2n, z), X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x)))), S3(x), e3), eta_step(2n, S3(x)))
170  +e5 = Equal.trans(Nat & U32, X.bl_step(1n, X.bl_step(2n, X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x)))))), X.bl_step(1n, S4(x)), S5(x), Equal.cong(Nat & U32, Nat & U32, z => X.bl_step(1n, z), X.bl_step(2n, X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x))))), S4(x), e4), eta_step(1n, S4(x)))
171  Equal.cong(Nat & U32, Nat, z => X.bl_fin(z), X.bl_step(1n, X.bl_step(2n, X.bl_step(4n, X.bl_step(8n, X.bl_step(16n, (0n, x)))))), S5(x), e5)