Logic and Math
A Logic Calculator
. Test if an argument is valid or invalid. Generate truth tables. Find counterexamples. etc.
Definitions from Quine's
. See how basic mathematical constructs can be reduced to statements about sets and classes.
Possible Worlds Semantics for Second-Order Modal Logic
. An unfinished attempt to define logic in terms of possible worlds.
Probability in Light of Independent Testimony for Mutually Exclusive Possibilities
. How to calculate probability from conflicting and corroborating testimony (under certain circumstances).
Musical Interval Explorer
. Hear arbitrary harmonic intervals and chords in any tuning in your browser.
Clock with Invented Hexadecimal Digits
. Rarely updated. Miscellaneous topics.