This is really strange in two ways.

One, you're not describing science but existence. Science is nothing if not a framework of knowledge based on the scientific method. To somehow come up with a definition of science that separates it from the scientific method actually removes all qualities of knowledge from science (do you think religious people also don't define their knowledge as "what is"?) On the whole, basing your definition of "Science" as how laymen define science seems to be a strange way to try to make a supposedly mathematical argument - from imprecision and abstraction?

Two, to conflate Science with existence essentially is concocting a truism - like when someone asks you to solve for x you've chosen to define x as whatever you want then solve it. Science as the sum of empirical human knowledge is an approximation of x, and as a mathematician I'm sure you understand the significance of how an approximation of something is a world apart from the thing itself. You cannot say that science is truth, therefore science is true - that is a pointless statement that completely drops all the reasons why science is more truthful than religious knowledge or any other form of knowledge.