Single Idea 13756

[catalogued under 5. Theory of Logic / H. Proof Systems / 5. Tableau Proof]

Full Idea

When the only rule of inference is Modus Ponens, the branches of a tree proof soon spread too wide for comfort.

Gist of Idea

A tree proof becomes too broad if its only rule is Modus Ponens

Source

David Bostock (Intermediate Logic [1997], 6.4)

Book Reference

Bostock,David: 'Intermediate Logic' [OUP 1997], p.263


Related Idea

Idea 9394 MPP: Given A and A→B, we may derive B [Lemmon]