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Proof step 28 from proof int2bytes-len-eq-pos (previous step)

int2bytes(i) = i2b(0) ' + bytes, # int2bytes(i) < 2, 0 ≤ i, i < 2 ^ (8 * (1 + n→i(# int2bytes(i) - 1 - 1))), i2b(0) ∈ int2bytes(i) ⊦ n = 0, bytes = [], # int2bytes(i) = n ↔ ¬ i < 2 ^ ((n→i(n) - 1) * 8 - 1) ∧ ¬ 2 ^ ((n→i(n) - 1) * 8) ≤ i

User applied rule insert rewrite lemma

And obtained the following new goals

Proof step 29:
⊦ n ≠ 1 → (n < 2 ↔ n = 0)

Rule argument

seq: ⊦ n ≠ 1 → (n < 2 ↔ n = 0) subst: [n] → [# int2bytes(i)] rotate: F spec: nat-basic1 inst: name: lstwo

Additional information

Used simplifier rules: int2bytes-zero: ⊦ int2bytes(i) = i2b(0) ' ↔ i = 0;%int2bytes-byte: ~128 ≤ i, i < 128 ⊦ int2bytes((* i)) = i2b(i) ';%int2bytes-empty: ⊦ int2bytes(i) ≠ [];% ⊦ # bytes = 0 ↔ bytes = [];% ⊦ # bytes = 1 ∧ by ∈ bytes → bytes = by '; (forward)% ⊦ i < j ∧ 0 ≤ i → 0 < j; (forward)% ⊦ m < n ∧ m = n0 → n0 < n; (forward)% ⊦ # by ' = 0 +1;% ⊦ by ' = by0 ' + bytes ↔ by = by0 ∧ bytes = [];% ⊦ (bytes + bytes0) + bytes1 = bytes + bytes0 + bytes1; Used terms: # int2bytes(i)