G4ip Prover

## 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.

Last modified: Sun May 10 18:18:13 GMT 1998