This is the equivalent of an
InputError for the up-conversion process,
indicating that a particular island of Presentation MathML created by SnuggleTeX
could not be up-converted to either Content MathML or Maxima input form. This
will be due to one of the following reasons:
-
The MathML falls outside the scope of what is supported by the up-conversion
process. (I.e. too complex)
-
The MathML is deemed to make no sense. (This is, of course, subjective as it
assumes the MathML is entered in a particular common form so one might reasonably
argue that this is just a special case of the last reason!)
See
UpConversionUtilities for methods to help with this, including a method
for converting these into error message Strings.