Was math discovered or invented ?

@SW-User Yes, and infinitesimals are the Holy Grail.

@helenS

@helenS ...for continuous things, perhaps...

@SomeMichGuy Yes. A function f(x) is continuous at x=x_0 if and only if an infinitesimal change of x_0 leads fo an infinitesimal change of f(x_0):
x_1 = x_0 + dx → f(x_1) = f(x_0) + dy.

@helenS You’re such an integral part of my life.

@Harmonium1923 Oh thaaank you!

@helenS Yes, I had the first semester of calculus, too. lol

But infinitesimals are creatures of continuous things, not discontinuous ones...and someone who quotes Kronecker probably knows that values associated with HIS δ are discrete (unlike those associated with the Dirac δ, which are continuous)...