Logical operations

Tarski and Mautner proposed to characterize the logical operations on a given domain as those invariant under arbitrary permutations. These operations are the ones that can be obtained as combinations of the operations on the following list: identity; substitution of variables; negation; finite or infinite disjunction; and existential quantification with respect to a finite or infinite block of variables. Inasmuch as every operation on this list is intuitively logical, this lends support to the Tarski-Mautner proposal.Thanks to Shaughan Levine, Gila Sher, and the referee for their help.