| x = 3 ' + 3 ' + 2 ', to4 = fail, x1 = x ∧ d0 = 1, h0 = head(x1) ⊦ 〈if h0 < d0 then to := fail else if h0 = d0 then { x1 := pop(x1) ; to := some(Leaf) } else let to0 = fail, to1 = fail in { build_rec#(d0 + 1; x1, to0) ; if to0 = fail then to := fail else { build_rec#(d0 + 1; x1, to1) ; if to1 = fail then to := fail else to := some(Node(to0 .t, to1 .t)) } }〉 〈to4 := to ; if to4 = fail then to0 := fail else to0 := some(Node(Leaf, to4 .t))〉 〈to1 := to0 ; if x1 ≠ [] then to1 := fail〉 to1 = some(Node(Leaf, Node(Node(Leaf, Leaf), Leaf))) |
x = 3 ' + 3 ' + 2 ', to4 = fail, x1 = x ∧ d0 = 1, h0 = head(x1) ⊦ 〈if h0 = d0 then { x1 := pop(x1) ; to := some(Leaf) } else let to0 = fail, to1 = fail in { build_rec#(d0 + 1; x1, to0) ; if to0 = fail then to := fail else { build_rec#(d0 + 1; x1, to1) ; if to1 = fail then to := fail else to := some(Node(to0 .t, to1 .t)) } }〉 〈to4 := to ; if to4 = fail then to0 := fail else to0 := some(Node(Leaf, to4 .t))〉 〈to1 := to0 ; if x1 ≠ [] then to1 := fail〉 to1 = some(Node(Leaf, Node(Node(Leaf, Leaf), Leaf)))
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ head(d ' + x) = d], [CSIMPSEQ : ⊦ (x + y) + z = x + y + z])]]