  Łukasiewicz invented a parenthesis-free logical notation. The idea consisted in writing logical constants before their arguments. Łukasiewicz replaced the usual signs for logical operations by letters: N (negation), K (conjunction), A (disjunction), C (implication) and E (equivalence). Any well-formed formula (the present explanations are restricted to propositional calculus) must begin with a capital letter (propositional variables are symbolized by lower-case Latin letters) which is the main functor of the entire formula. The main connective has as its arguments variables or formulas consisting of variables and constants. The following are examples: Cpp for (p → p), CCppNq for ((p → p) → ¬q). The structure of a formula (and hence also its meaning) in Polish notation is uniquely determined by the position of the letters. The parenthesis-free notation is unambiguous in the sense that any finite sequence of symbols for connectives and variables is interpretable in a unique way. This implies that any wff coded in Polish notation has only one translation into the standard symbolism. The main advantage of Polish notation is its economy, because it avoids special punctuation devices such as brackets or dots. When Łukasiewicz met Turing in 1949, the latter remarked that Polish notation was much better for computers, because formulas with function-symbols in front could be better elaborated by mechanical devices.