a1 Department of Mathematics, University College Galway, Galway, Ireland
Existence principles are given for systems of differential equations with reflection of the argument. These are derived using fixed point analysis, specifically the Nonlinear Alternative. Then existence results are deduced for certain classes of first and second order equations with reflection of the argument.
(Received January 31 1992)
1991 Mathematics subject classification (Amer. Math. Soc)