In the present paper, we prove the Yang-Baxter relations for a specific R-matrix dependent on the spectral parameter. For the simpliest Lax operator connected with the trigonometric case of the main commutation relation, this R-matrix plays the role of the fundamental R-matrix in the sense of [1]. Now we describe this Lax operator.Let P and Q be the Heisenberg pair of self-adjoint operators with the commutation relationWe regard the real number 7 as a dimensionless coupling constant and put the Planck constant h equal to 1. We construct the Weyl pair of unitary operatorssatisfying the commutation relationThe quantum space 7/, where P and Q are represented irreducibly, can be realized as L2(IR) with r such that
Or
= ~r pc(x) _ ~ d i ~ r (4)(coordinate representation). In the sequel, a specific realization of P and Q is not significant. The Lax operator acts in the-tensor product of the quantum space 7/and the auxiliary space 12 = C 2 and can be given by a 2 • 2-matrix whose entries are operators on 7/, U xV)Here, z is a complex number called the spectral parameter. The indices f and a stand for the quantum and auxiliary spaces where Lf, a(x ) acts. In this notation, the main commutation relation (cf.[2]) can conveniently be written in the following form:which is regarded as a relation in 7"l @ 1)1 | ~22. Here, Ral,a2(x) is an operator in the tensor product 1) | 1) = C 4 which can be given by the 4