{motive : Lean.Meta.AC.PreExpr → Sort u} →
  ((lhs rhs : Lean.Meta.AC.PreExpr) → motive lhs → motive rhs → motive (lhs.op rhs)) →
    ((e : Lean.Expr) → motive (Lean.Meta.AC.PreExpr.var e)) → (t : Lean.Meta.AC.PreExpr) → motive t