Polish notation was created by Jan Łukasiewicz. Operators are placed before operands.

Np negation ~ p
Kpq conjunction p ∧ q
Apq disjunction p ∨ q
Cpq material implication p → q
Epq material equivalence p ↔ q
PxFx universal quantifier ∀ x, Fx
SxGx existential quantifier ∃ x, Gx