Deletion of Exact couple

Comment: To answer the question in the nominator's second sentence: the right answer is probably MathSciNet, but Google scholar works well enough and doesn't require a subscription. There you will find approximately 1000 publications mentioning this topic. MathSciNet has 20 with that phrase in the title, most or all of which are probably for this meaning of the phrase. That's easily enough for , the only relevant notability criterion for scientific concepts. And of course just because you can't math doesn't mean everyone else has to be handicapped to your level of ignorance — we all have some subject here that we don't understand, but that doesn't mean the encyclopedia should contain nothing
Stance: keep
Cited policy: Wikipedia:Notability (WP:GNG)