Article
Keywords:
cardinal sum; cardinal product; ordinal sum; ordinal product; $n$-ary relational system; $n$-ary ordered set; cardinal power; ordinal power
Summary:
The aim of this paper is to define and study cardinal (direct) and ordinal operations of addition, multiplication, and exponentiation for $n$-ary relational systems. $n$-ary ordered sets are defined as special $n$-ary relational systems by means of properties that seem to suitably generalize reflexivity, antisymmetry, and transitivity from the case of $n=2$ or 3. The class of $n$-ary ordered sets is then closed under the cardinal and ordinal operations.
References:
                        
[3] G. Birkhoff: 
Lattice Theory. Amer. Math. Soc., Providence, Rhode Island, Third Edition, 1973. 
MR 0227053[5] V. Novák: 
On a power of relational structures. Czechoslovak Math. J. 35 (1985), 167-172. 
MR 0779345[6] V. Novák M. Novotný: 
Binary and ternary relations. Math. Bohem. 117(1992), 283-292. 
MR 1184541[7] V. Novák M. Novotný: 
Pseudodimension of relational structures. Czechoslovak Math. J. (submitted). 
MR 1708362[8] J. Šlapal: 
Direct arithmetics of relational systems. Publ. Math. Debrecen 38 (1991), 39-48. 
MR 1100904