The Logic Resource Center

The Logic Resource Center

Public Alpha

The Logic Resource Center

Public Alpha

© 2025 The Logic Resource Center, LLC

Conjunction Introduction

Conjunction Introduction is probably one of the least often denied classical rules of inference.

Constants: &
Systems: LRC_F OLI The Logic Book LRC LRC_P LRC_O

Start a Problem →

Conjunction Introduction

i.

ϕ

ii.

ψ

⋮

iii.

ϕ&ψ

&I: i, ii

Forward

Select any two available claims
Click "Apply"

Backward

Select a goal conjunction
Click "Apply"

Preview shown for the Point And Click derivation type in the LRC system