\input texinfo @c -*-texinfo-*-

@node Top
@top Tests

@tex
  \gdef\Desig{\buildrel \rm def \over \equiv}
@end tex

@c MathJax process LaTeX commands in math environments
@c trailing space is needed for latex2html
@c tex4ht httex does not keep the definition with \def
@c in @math, which seems correct as \def is only defined
@c within the math group
@ifset tex4ht
@math{\gdef\otest{\sqrt{64}} }
@end ifset
@ifclear tex4ht
@math{\def\otest{\sqrt{64}} }
@end ifclear

@c MathJax doesn't get \gdef
@math{\gdef\testmacro{a \equiv b} }

@math{\Desig \testmacro \otest}

@displaymath
 \Desig \testmacro \otest
@end displaymath

@bye