Theorem: LRAT.DefaultFormula.insertRatUnits_preserves_assignments_invariant
Proof state before:
case inl
n : Nat
f : DefaultFormula n
hf : f.ratUnits = #[] ∧ f.assignments_invariant
units : List (Literal (PosFin n))
h :
  let assignments := (f.insertRatUnits units).fst.assignments;
  let_fun hsize := ⋯;
  let ratUnits := (f.insertRatUnits units).fst.ratUnits;
  insertUnit_invariant f.assignments ⋯ ratUnits assignments hsize
hsize : (f.insertRatUnits units).fst.assignments.size = n
i : PosFin n
b : Bool
hb : hasAssignment b (f.insertRatUnits units).fst.assignments[i.val] = true
p : PosFin n → Bool
hp :
  ∀ (x : DefaultClause n),
    (some x ∈ (f.insertRatUnits units).fst.clauses.data ∨
        (∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, true) = x) ∨
          ∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, true) = x) →
      ∃ a, (a, false) ∈ Clause.toList x ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList x ∧ p a = true
c : DefaultClause n
cf : some c ∈ f.clauses.data
⊢ ∃ a, (a, false) ∈ Clause.toList c ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList c ∧ p a = true

case inr.inl
n : Nat
f : DefaultFormula n
hf : f.ratUnits = #[] ∧ f.assignments_invariant
units : List (Literal (PosFin n))
h :
  let assignments := (f.insertRatUnits units).fst.assignments;
  let_fun hsize := ⋯;
  let ratUnits := (f.insertRatUnits units).fst.ratUnits;
  insertUnit_invariant f.assignments ⋯ ratUnits assignments hsize
hsize : (f.insertRatUnits units).fst.assignments.size = n
i : PosFin n
b : Bool
hb : hasAssignment b (f.insertRatUnits units).fst.assignments[i.val] = true
p : PosFin n → Bool
hp :
  ∀ (x : DefaultClause n),
    (some x ∈ (f.insertRatUnits units).fst.clauses.data ∨
        (∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, true) = x) ∨
          ∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, true) = x) →
      ∃ a, (a, false) ∈ Clause.toList x ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList x ∧ p a = true
c : DefaultClause n
cf : ∃ a, (a, false) ∈ f.rupUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.rupUnits.data ∧ unit (a, true) = c
⊢ ∃ a, (a, false) ∈ Clause.toList c ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList c ∧ p a = true

case inr.inr
n : Nat
f : DefaultFormula n
hf : f.ratUnits = #[] ∧ f.assignments_invariant
units : List (Literal (PosFin n))
h :
  let assignments := (f.insertRatUnits units).fst.assignments;
  let_fun hsize := ⋯;
  let ratUnits := (f.insertRatUnits units).fst.ratUnits;
  insertUnit_invariant f.assignments ⋯ ratUnits assignments hsize
hsize : (f.insertRatUnits units).fst.assignments.size = n
i : PosFin n
b : Bool
hb : hasAssignment b (f.insertRatUnits units).fst.assignments[i.val] = true
p : PosFin n → Bool
hp :
  ∀ (x : DefaultClause n),
    (some x ∈ (f.insertRatUnits units).fst.clauses.data ∨
        (∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, true) = x) ∨
          ∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, true) = x) →
      ∃ a, (a, false) ∈ Clause.toList x ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList x ∧ p a = true
c : DefaultClause n
cf : ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c
⊢ ∃ a, (a, false) ∈ Clause.toList c ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList c ∧ p a = true
Tactic:
. specialize hp c (Or.inl cf)
  exact hp
Proof state after:
case inr.inl
n : Nat
f : DefaultFormula n
hf : f.ratUnits = #[] ∧ f.assignments_invariant
units : List (Literal (PosFin n))
h :
  let assignments := (f.insertRatUnits units).fst.assignments;
  let_fun hsize := ⋯;
  let ratUnits := (f.insertRatUnits units).fst.ratUnits;
  insertUnit_invariant f.assignments ⋯ ratUnits assignments hsize
hsize : (f.insertRatUnits units).fst.assignments.size = n
i : PosFin n
b : Bool
hb : hasAssignment b (f.insertRatUnits units).fst.assignments[i.val] = true
p : PosFin n → Bool
hp :
  ∀ (x : DefaultClause n),
    (some x ∈ (f.insertRatUnits units).fst.clauses.data ∨
        (∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, true) = x) ∨
          ∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, true) = x) →
      ∃ a, (a, false) ∈ Clause.toList x ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList x ∧ p a = true
c : DefaultClause n
cf : ∃ a, (a, false) ∈ f.rupUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.rupUnits.data ∧ unit (a, true) = c
⊢ ∃ a, (a, false) ∈ Clause.toList c ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList c ∧ p a = true

case inr.inr
n : Nat
f : DefaultFormula n
hf : f.ratUnits = #[] ∧ f.assignments_invariant
units : List (Literal (PosFin n))
h :
  let assignments := (f.insertRatUnits units).fst.assignments;
  let_fun hsize := ⋯;
  let ratUnits := (f.insertRatUnits units).fst.ratUnits;
  insertUnit_invariant f.assignments ⋯ ratUnits assignments hsize
hsize : (f.insertRatUnits units).fst.assignments.size = n
i : PosFin n
b : Bool
hb : hasAssignment b (f.insertRatUnits units).fst.assignments[i.val] = true
p : PosFin n → Bool
hp :
  ∀ (x : DefaultClause n),
    (some x ∈ (f.insertRatUnits units).fst.clauses.data ∨
        (∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.rupUnits.data ∧ unit (a, true) = x) ∨
          ∃ a,
            (a, false) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, false) = x ∨
              (a, true) ∈ (f.insertRatUnits units).fst.ratUnits.data ∧ unit (a, true) = x) →
      ∃ a, (a, false) ∈ Clause.toList x ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList x ∧ p a = true
c : DefaultClause n
cf : ∃ a, (a, false) ∈ f.ratUnits.data ∧ unit (a, false) = c ∨ (a, true) ∈ f.ratUnits.data ∧ unit (a, true) = c
⊢ ∃ a, (a, false) ∈ Clause.toList c ∧ decide (p a = false) = true ∨ (a, true) ∈ Clause.toList c ∧ p a = true