This is some sort of mapping, used to add rigour to math, such as addition, subtraction. Among many other things that I hope to document in the future.
A map, from the domain to the range.
injectiv := one-to-one := if f(x1) = f(x2) ⟹ x1 = x2.
This intuitively means that each input maps to a unique output.
surjectiv := onto := If for f : A → B, ∀y ∈ B, ∃x ∈ A : y = f(x)f
is a surjection. AKA Let f : X → Y. We say
f is surjective if
for all y ∈ Y, there
exists x ∈ X such
that y = f(x). This
intuitively means that for every possible output there is some input
that is sent to it.
bijective := invertible := injective and
surjective.
natural domai := This is an informal term to describe a
domain that is natural. That is to say for what domain is the function
well defined, so no division by 0 or no logs of negatives or negative of
sqrts
[[set___11_06_2022__090230149]] TODO
tags math