Prover for G4ip (LJT)

Readme
Formulae:    F ::= false | A | F & F | F v F | F -> F | F <-> F | (F)
Sequents:     => F     or     [F,]* F => F
Inference Rules: html, dvi or ps.
Start: starts the proof search, Clear: clears the text fields,
Next: searches for the next proof, Stop: stops the proof search.

Provable Examples:
=> (p v (q v r)) <-> ((p v q) v r)
=> (p & (q & r)) <-> ((p & q) & r)
=> (p & (q v r)) <-> ((p & q) v (p & r))
=> (p v (q & r)) <-> ((p v q) & (p v r))
=> (p -> p) -> (p -> p)
=> (a -> (b -> c)) -> ((a -> b) -> (a -> c))
=> a -> ((a -> b) -> a)
=> b -> ((a -> b) -> b)
=> (a & b) -> (b & a)
=> (a -> (a -> b)) -> (a -> b)
=> ((((p -> q) -> p) -> p) -> q) -> q
=> (a v (a -> b)) -> (((a -> b) -> a)-> a)
=> (a -> (b -> false)) -> (b -> (a -> false))
=> ((a v (a -> false))-> false)-> false
a & b, c & d => b & c
(a v (a-> false)) -> false => false
Non-Provable Examples:
=> ((a -> b) -> a) -> a
=> a v (a -> false)
=> (a & b v (((( a-> flase) -> false) -> q) v (b -> q)) -> q) -> q
Some advanced examples
Source Code: Formulae, Contexts, Sequents, ProofDisplay, Prover, Parser, Applet

Lambda Prolog Version: The programm G4ip.mod can be executed using Terzo Another implementation of G4ip by Joshua Hodas and Dale Miller written in Lolli can be found here.
Christian Urban

Last modified: Sun May 10 18:18:28 GMT 1998