Every Pointfree Funcoid on a Semilattice is an Algebraic Structure
Continuing this blog post: The set of all pointfree funcoids on upper semilattices with least elements is exactly a certain algebraic structure defined by propositional formulas. Really just add the identities defining a pointfree funcoid to the identities of an upper semilattice with least element. I will list the exact list of identities defining a […]
Funcoid is a “Structure” in the Sense of Math Logic
A few seconds ago I realized that certain cases of pointfree funcoids can be described as a structure in the sense of mathematical logic, that is as a finite set of operations and relational symbols. Precisely, if a pointfree funcoid $latex f$ is defined on a lattice (or semilattice) with a least element $latex \bot$, […]
My old files related with math logic
In 2005 year I put online some math articles related with formulas and math logic (despite I am not a professional logician). In 2005 I like a crackpot thought that I discovered a completely new math method replacing axiomatic method. This was a huge error (my skipped proof was just wrong). After that the files […]
How proof by contradiction differs of direct proof
This my post is about mathematical logic, but first I will explain the story about people who asked or answer this question. A famous mathematician Timoty Gowers asked this question: What is the difference between direct proofs and proofs by contradiction. We, people, are capable of doing irrational things and to be discouraged. I wrote […]