In this paper, we introduced the concept of pseudo-commutators in BCK-algebras and then we state and prove some related theorems on these notions. Mathematics Subject Classification: Primary: 06F35 ; Secondary: 08A05, 03G25.

A minimal formula of a given logic L is a formula which is provable in L and is not a non-trivial substitution instance of other provable formulas in L. In [5], Y. Komori asked whether normal proofs of minimal formulas are unique in the implicational fragments of natural deduction systems for the intuitionistic logic and the logic BCK. It was already shown that the answer is positive for BCK, w...

Pseudo equality algebras were initially introduced by Jenei and Kóródi as a possible algebraic semantic for fuzzy type theory, and they have been revised by Dvurečenskij and Zahiri under the name of JK-algebras. The aim of this paper is to investigate the internal states and the state-morphisms on pseudo equality algebras. We define and study new classes of pseudo equality algebras, such as com...

Equilibrium moisture contents (EMCs) and diffusion coefficients of a high pressure laminate (HPL) overlay, a wood particleboard (PB) substrate, and an HPL backer (BCK) were measured at different levels of relative humidity (RH). The EMCs as a function of RH were fitted to the Nelson's sorption isotherm. It was found that Nelson's model reproduced accurately the experimental data of these differ...