Symbolic Logic Tools How Logic Works

Model Checker

Describe a finite structure, then ask whether a closed sentence is true in it.

Domain

The elements the structure is built from, separated by commas.

Constants

Which element each name picks out. Leave empty if the language has no constants.

Constant
Denotes

Symbols

Each predicate, its arity, and what it is true of.

Symbol
Arity
Extension / value

Arity 0 takes T or F. Arity 1 takes elements, e.g. a,b. Arity 2–3 take tuples, e.g. <a,b>, <b,a>.

Sentence

A closed sentence to evaluate in the structure above.

ASCII shorthands work: -> for →, ~ for ¬, /\ for ∧, \/ for ∨.