Theorem: LRAT.DefaultFormula.mem_of_insertRupUnits
Proof state before:
case inr.inl.intro.inr.intro
n : Nat
f : DefaultFormula n
units : List (Literal (PosFin n))
c : DefaultClause n
hb : ∀ (l : Literal (PosFin n)), l ∈ (f.rupUnits, f.assignments, false).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
hl :
  ∀ (acc : Array (Literal (PosFin n)) × Array Assignment × Bool),
    (∀ (l : Literal (PosFin n)), l ∈ acc.fst.data → l ∈ f.rupUnits.data ∨ l ∈ units) →
      ∀ (unit : Literal (PosFin n)),
        unit ∈ units → ∀ (l : Literal (PosFin n)), l ∈ (insertUnit acc unit).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
h_insertUnit_fold :
  ∀ (l : Literal (PosFin n)),
    l ∈ (List.foldl insertUnit (f.rupUnits, f.assignments, false) units).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
i : PosFin n
h1 : (i, true) ∈ (List.foldl insertUnit (f.rupUnits, f.assignments, false) units).fst.data
h2 : unit (i, true) = c
⊢ (∃ a, (a, false) ∈ units ∧ Clause.unit (a, false) = c ∨ (a, true) ∈ units ∧ Clause.unit (a, true) = c) ∨
    some c ∈ f.clauses.data ∨
      (∃ a, (a, false) ∈ f.rupUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.rupUnits.data ∧ unit (a, true) = c) ∨
        ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c

case inr.inr
n : Nat
f : DefaultFormula n
units : List (Literal (PosFin n))
c : DefaultClause n
hb : ∀ (l : Literal (PosFin n)), l ∈ (f.rupUnits, f.assignments, false).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
hl :
  ∀ (acc : Array (Literal (PosFin n)) × Array Assignment × Bool),
    (∀ (l : Literal (PosFin n)), l ∈ acc.fst.data → l ∈ f.rupUnits.data ∨ l ∈ units) →
      ∀ (unit : Literal (PosFin n)),
        unit ∈ units → ∀ (l : Literal (PosFin n)), l ∈ (insertUnit acc unit).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
h_insertUnit_fold :
  ∀ (l : Literal (PosFin n)),
    l ∈ (List.foldl insertUnit (f.rupUnits, f.assignments, false) units).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
h : ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c
⊢ (∃ a, (a, false) ∈ units ∧ Clause.unit (a, false) = c ∨ (a, true) ∈ units ∧ Clause.unit (a, true) = c) ∨
    some c ∈ f.clauses.data ∨
      (∃ a, (a, false) ∈ f.rupUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.rupUnits.data ∧ unit (a, true) = c) ∨
        ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c
Tactic:
. rcases h_insertUnit_fold (i, true) h1 with h_insertUnit_fold | h_insertUnit_fold
  . apply Or.inr ∘ Or.inr ∘ Or.inl ∘ Exists.intro i ∘ Or.inr
    exact ⟨h_insertUnit_fold, h2⟩
  . apply Or.inl ∘ Exists.intro i ∘ Or.inr
    exact ⟨h_insertUnit_fold, h2⟩
Proof state after:
case inr.inr
n : Nat
f : DefaultFormula n
units : List (Literal (PosFin n))
c : DefaultClause n
hb : ∀ (l : Literal (PosFin n)), l ∈ (f.rupUnits, f.assignments, false).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
hl :
  ∀ (acc : Array (Literal (PosFin n)) × Array Assignment × Bool),
    (∀ (l : Literal (PosFin n)), l ∈ acc.fst.data → l ∈ f.rupUnits.data ∨ l ∈ units) →
      ∀ (unit : Literal (PosFin n)),
        unit ∈ units → ∀ (l : Literal (PosFin n)), l ∈ (insertUnit acc unit).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
h_insertUnit_fold :
  ∀ (l : Literal (PosFin n)),
    l ∈ (List.foldl insertUnit (f.rupUnits, f.assignments, false) units).fst.data → l ∈ f.rupUnits.data ∨ l ∈ units
h : ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c
⊢ (∃ a, (a, false) ∈ units ∧ Clause.unit (a, false) = c ∨ (a, true) ∈ units ∧ Clause.unit (a, true) = c) ∨
    some c ∈ f.clauses.data ∨
      (∃ a, (a, false) ∈ f.rupUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.rupUnits.data ∧ unit (a, true) = c) ∨
        ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c