The simplified forms of generalized magnetohydrodynamic equations have been
derived. The K. Appert theory and Hain-Lust equation are two special cases
of our results when p --> 0 and omega/omega (ei) --> 0. It is shown that t
he process of taking any limits (p --> 0 or omega/omega (ei) --> 0) will re
sult in a singularity at the Alfven resonant layer.