Lean4
/-- If the expression is a function application of `fName` with 7 arguments, return those arguments.
Otherwise return `none`. -/
@[inline]
def _root_.Lean.Expr.app7? (e : Expr) (fName : Name) : Option (Expr × Expr × Expr × Expr × Expr × Expr × Expr) :=
if e.isAppOfArity fName 7 then
some
(e.appFn!.appFn!.appFn!.appFn!.appFn!.appFn!.appArg!, e.appFn!.appFn!.appFn!.appFn!.appFn!.appArg!,
e.appFn!.appFn!.appFn!.appFn!.appArg!, e.appFn!.appFn!.appFn!.appArg!, e.appFn!.appFn!.appArg!,
e.appFn!.appArg!, e.appArg!)
else none