Definition:Łukasiewicz's Polish Notation

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Definition

Łukasiewicz's Polish notation is a system of prefix notation for propositional logic.

Statements are represented by lowercase letters, as the conventional notation.

Logical connectives are represented by uppercase letters as follows:

Connective Conventional symbology Łukasiewicz's Polish notation
Negation $\lnot p$ $\operatorname N p$
Conjunction $p \land q$ $\operatorname K p q$
Implication $p \implies q$ $\operatorname C p q$
Disjunction $p \lor q$ $\operatorname A p q$
Biconditional $p \iff q$ $\operatorname E p q$


Examples

Arbitrary Example

The compound statement expresssed in infix notation as:

$\paren {p \land \lnot q} \implies \paren {p \lor \lnot r}$

would be expressed in Łukasiewicz's Polish notation as:

$\operatorname C \operatorname K p \operatorname N q \operatorname A p \operatorname N r$


Also see

  • Results about Łukasiewicz's Polish notation can be found here.


Source of Name

This entry was named for Jan Łukasiewicz.


Historical Note

Łukasiewicz's Polish notation was introduced by Jan Łukasiewicz in $1920$ as a parenthesis-free notation for propositional logic.


Sources