Go backward to ContradictionsGo up to TopGo forward to Example |

A contradiction is usually derived by establishing a proof situation

Kunion {G, ~G}F(alse)

because we then immediately have

~~>

Kunion {G, ~G}F(alse) ~~>

Kunion {F(alse)}F(alse) .

Kunion {F(alse)}

*Try to prove a formula that contradicts some given knowledge.*

Author: Wolfgang Schreiner

Last Modification: November 30, 1999