I am defending the usefulness of modern logic to a class and I came across this modalized version of a Thomistic argument (https://www.bu.edu/wcp/Papers/Reli/ReliMayd.htm). However, although I have studied both predicate and modal logic before, some of this gentleman's notations confuse me immensely. Namely, I have never seen (3t) for example, or a modal quantifier within the exact same parentheses as an existential quantifier.
P.S. with respect to natural deduction proofs, I am looking for something like this:
- (P -> Q)
- W1: P .... 2, Possible Instantiation.
- W1: P -> Q ..... 3, Necessary Instantiation
- W1: Q ..... 3,4 Modus Ponens
- <>Q ..... 5, Possible Generalization.