Module: Mathlib.Data.Ordmap.Invariants

Goal state before:
pp: case pos.node.nil
α : Type u_1
x : α
ls : ℕ
ll : Ordnode α
lx : α
lr : Ordnode α
hl : (node ls ll lx lr).Balanced
sl : (node ls ll lx lr).Sized
rs : ℕ
rx : α
h : delta * ls < rs
rls : ℕ
rll : Ordnode α
rlx : α
rlr : Ordnode α
hr : (node rs (node rls rll rlx rlr) rx nil).Balanced
sr : (node rs (node rls rll rlx rlr) rx nil).Sized
rd : delta ≤ (node rls rll rlx rlr).size + nil.size
⊢ (node ls ll lx lr).rotateL x (node rs (node rls rll rlx rlr) rx nil) =
    rec nil
      (fun size l x_1 r l_ih r_ih ↦
        rec nil
          (fun size_1 l_1 x_2 r_1 l_ih r_ih ↦
            if size < ratio * size_1 then
              node (ls + rs + 1) (node (ls + size + 1) (node ls ll lx lr) x (node rls rll rlx rlr)) rx nil
            else
              node (ls + rs + 1) (node (ls + l.size + 1) (node ls ll lx lr) x l) x_1
                (node (r.size + size_1 + 1) r rx nil))
          nil)
      (node rls rll rlx rlr)

pp: case pos.node.node
α : Type u_1
x : α
ls : ℕ
ll : Ordnode α
lx : α
lr : Ordnode α
hl : (node ls ll lx lr).Balanced
sl : (node ls ll lx lr).Sized
rs : ℕ
rx : α
h : delta * ls < rs
rls : ℕ
rll : Ordnode α
rlx : α
rlr : Ordnode α
rrs : ℕ
rrl : Ordnode α
rrx : α
rrr : Ordnode α
hr : (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)).Balanced
sr : (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)).Sized
rd : delta ≤ (node rls rll rlx rlr).size + (node rrs rrl rrx rrr).size
⊢ (node ls ll lx lr).rotateL x (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)) =
    rec nil
      (fun size l x_1 r l_ih r_ih ↦
        rec nil
          (fun size_1 l_1 x_2 r_1 l_ih r_ih ↦
            if size < ratio * size_1 then
              node (ls + rs + 1) (node (ls + size + 1) (node ls ll lx lr) x (node rls rll rlx rlr)) rx
                (node rrs rrl rrx rrr)
            else
              node (ls + rs + 1) (node (ls + l.size + 1) (node ls ll lx lr) x l) x_1
                (node (r.size + size_1 + 1) r rx (node rrs rrl rrx rrr)))
          (node rrs rrl rrx rrr))
      (node rls rll rlx rlr)

Tactic:
· exact absurd (le_trans rd (balancedSz_zero.1 hr.1)) (by decide)

Goal state after:
case pos.node.node
α : Type u_1
x : α
ls : ℕ
ll : Ordnode α
lx : α
lr : Ordnode α
hl : (node ls ll lx lr).Balanced
sl : (node ls ll lx lr).Sized
rs : ℕ
rx : α
h : delta * ls < rs
rls : ℕ
rll : Ordnode α
rlx : α
rlr : Ordnode α
rrs : ℕ
rrl : Ordnode α
rrx : α
rrr : Ordnode α
hr : (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)).Balanced
sr : (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)).Sized
rd : delta ≤ (node rls rll rlx rlr).size + (node rrs rrl rrx rrr).size
⊢ (node ls ll lx lr).rotateL x (node rs (node rls rll rlx rlr) rx (node rrs rrl rrx rrr)) =
    rec nil
      (fun size l x_1 r l_ih r_ih ↦
        rec nil
          (fun size_1 l_1 x_2 r_1 l_ih r_ih ↦
            if size < ratio * size_1 then
              node (ls + rs + 1) (node (ls + size + 1) (node ls ll lx lr) x (node rls rll rlx rlr)) rx
                (node rrs rrl rrx rrr)
            else
              node (ls + rs + 1) (node (ls + l.size + 1) (node ls ll lx lr) x l) x_1
                (node (r.size + size_1 + 1) r rx (node rrs rrl rrx rrr)))
          (node rrs rrl rrx rrr))
      (node rls rll rlx rlr)