...whatever remains, however IMPROBABLE,
must be the truth."
The Big Bang Theory Season 8, Episode 1
Improbable.
Money Heist Season 3, Episode 8
Well, if we accept your premise and also
accept the highly IMPROBABLE assumption...
The Big Bang Theory Season 1, Episode 17
I believe what you meant to say is,
"I give up. He's IMPROBABLE."
The Big Bang Theory Season 3, Episode 3