| lax.head = @(m0, m1), abs-padding(buf1) ∧ abs-nodes(buf0, m + # buf1, a ' + x, lax, weak) ∨ lax ≠ [] ∧ m0 = m ∧ m1 = # buf1 ∧ abs-node(buf1, a) ∧ abs-nodes(buf0, m + # buf1, x, lax.tail, weak), ∀ buf2, m, a, x, lax, weak. # buf2 < #(buf1 + buf0) → abs-nodes(buf2, m, a ' + x, lax, weak) → (∃ lax0. lax = lax.head ' + lax0) ⊦ ∃ lax0. lax = @(m0, m1) ' + lax0 |
lax.head = @(m0, m1), abs-nodes(buf0, m + # buf1, a ' + x, lax, weak), abs-padding(buf1), ∀ buf2, m, a, x, lax, weak. # buf2 < #(buf1 + buf0) → abs-nodes(buf2, m, a ' + x, lax, weak) → (∃ lax0. lax = lax.head ' + lax0) ⊦ ∃ lax0. lax = @(m0, m1) ' + lax0
lax.head = @(m0, m1), m0 = m, m1 = # buf1, abs-node(buf1, a), abs-nodes(buf0, m + # buf1, x, lax.tail, weak), ∀ buf2, m, a, x, lax, weak. # buf2 < #(buf1 + buf0) → abs-nodes(buf2, m, a ' + x, lax, weak) → (∃ lax0. lax = lax.head ' + lax0) ⊦ lax = [], ∃ lax0. lax = @(m0, m1) ' + lax0