certainty

• Proof positive

  Undeniable evidence that conclusively demonstrates a fact or conclusion, leaving no room for doubt.

• A foregone conclusion

  Something that is certain to happen or has already been decided, making any further discussion or action pointless.

• A lead pipe cinch

  Something that is absolutely certain to happen or incredibly easy to achieve.

• Without question

  Used to emphasize that something is absolutely true, certain, or undeniable.