or! You can't use `\spacefactor' in vertical mode. \@->\spacefactor \@m
or simply! You can't use `\spacefactor' in math mode. \@->\spacefactor \@m
bite the LaTeX programmer who uses an internal command without taking “precautions”. An internal-style command such as! Improper \spacefactor. ...
@foohas been defined or used in a private macro, and it is interpreted as
@, followed by the ‘text’
@is used, for real, to set up end-of-sentence space in some circumstances; it uses
spacefactorto do that.) The problem is discussed in detail in “
@in macro names”, together with solutions.
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