inductionGen.lean:23:2-23:14: error: Invalid target: Index in target's type is not a variable (consider using the `cases` tactic instead)
  n + 1
case cons
α : Type u_1
n : Nat
ys : Vec α (n + 1)
x : α
xs : Vec α n
h : Vec.cons x xs = ys
⊢ (Vec.cons x xs).head = ys.head
inductionGen.lean:25:8-25:11: warning: declaration uses `sorry`
case natVal
α : ExprType
a✝ : Nat
b : Expr ExprType.nat
h : Expr.natVal a✝ = b
⊢ eval (constProp (Expr.natVal a✝)) = eval b

case boolVal
α : ExprType
a✝ : Bool
b : Expr ExprType.bool
h : Expr.boolVal a✝ = b
⊢ eval (constProp (Expr.boolVal a✝)) = eval b

case eq
α α✝ : ExprType
a✝¹ a✝ : Expr α✝
a_ih✝¹ : ∀ (b : Expr α✝), a✝¹ = b → eval (constProp a✝¹) = eval b
a_ih✝ : ∀ (b : Expr α✝), a✝ = b → eval (constProp a✝) = eval b
b : Expr ExprType.bool
h : a✝¹.eq a✝ = b
⊢ eval (constProp (a✝¹.eq a✝)) = eval b

case add
α : ExprType
a✝¹ a✝ : Expr ExprType.nat
a_ih✝¹ : ∀ (b : Expr ExprType.nat), a✝¹ = b → eval (constProp a✝¹) = eval b
a_ih✝ : ∀ (b : Expr ExprType.nat), a✝ = b → eval (constProp a✝) = eval b
b : Expr ExprType.nat
h : a✝¹.add a✝ = b
⊢ eval (constProp (a✝¹.add a✝)) = eval b
inductionGen.lean:64:8-64:11: warning: declaration uses `sorry`
inductionGen.lean:78:2-78:27: error: Invalid target: Target (or one of its indices) occurs more than once
  n