KWHMath

In logic, we consider a proposition $A$ and its negation $\lnot A$. If we have a logical implication $A\to B$,  then we also have its contra...

Our goal is to compare these familiar, basic structures. All of these, except for set, are simple examples of functions. For ready compariso...

We want to establish a string of equalities. That string will use several substitutions which involve basis expansions,  so it is helpful to...

\[ \boxed { \begin{array} {} & \text {Preorders = Thin Categories} & \\ & \text {reflexive:} \; x \leq x & \\ & \text {t...

There are several groups that play an important role in linear algebra and elementary geometry. The following table shows what they are and ...