The Logic Resource Center
Public Alpha
Systems
Open options
Systems
The Logic Resource Center
Public Alpha
Systems
Open options
Systems
LRC_O
Like the base system LRC_F, but allows open sentences
Start a Problem
→
Constants
¬
&
∨
→
↔
∀
∃
=
⊥
Example Formula
∀
x
∀
y
(
x
=
y
→
(
L
x
↔
L
y
)
)
Term Extensions
F
1
a
2
x
3
Allow Open Sentences
Yes
Known Issues
None
Problem Types
Typed Forward Strict Derivation
Point And Click Derivation
Experimental Point And Click Tableau
Experimental Free Tableau
Derivation Rules
Typed Forward Strict
A: Assumption
R: Reiteration
&E: Conjunction Elimination
&I: Conjunction Introduction
∨E: Disjunction Elimination
∨I: Disjunction Introduction
→E: Conditional Elimination
→I: Conditional Introduction
↔E: Biconditional Elimination
↔I: Biconditional Introduction
¬I: Negation Introduction
⊥I: Falsum Introduction
¬E: Negation Elimination
⊥E: Falsum Elimination
∃E: Existential Elimination
∃I: Existential Introduction
∀E: Universal Elimination
∀I: Universal Introduction
=E: Identity Elimination
=I: Identity Introduction
Point And Click
A: Assumption
R: Reiteration
&E: Conjunction Elimination
&I: Conjunction Introduction
∨E: Disjunction Elimination
∨I: Disjunction Introduction
→E: Conditional Elimination
→I: Conditional Introduction
↔E: Biconditional Elimination
↔I: Biconditional Introduction
¬I: Negation Introduction
⊥I: Falsum Introduction
¬E: Negation Elimination
⊥E: Falsum Elimination
∃E: Existential Elimination
∃I: Existential Introduction
∀E: Universal Elimination
∀I: Universal Introduction
=E: Identity Elimination
=I: Identity Introduction