Integrable delay-difference and delay-differential analogs of the KdV, Boussinesq, and KP equations

Delay-difference and delay-differential analogues of the KdV Boussinesq (BSQ) equations are presented. Each them has N-soliton solution reduces to an already known soliton equation as delay parameter approaches 0. In addition, a analogue KP is proposed. We discuss its limit Finally, relationship between KdV, BSQ, clarified. Namely, reductions yield BSQ equations.