Reply To: Spacing of Function Names
I took your advice and contacted both BANA and ICEB. Below is the answer to our question regarding section 9.3 of the GTM.
Your primary thought to follow print is correct in my estimation. As you have noted, math often is not precise in it's use of spacing in print. They may use "half" spacing or may present equations across the print line, expanding or contracting the spaces to allow it to fit. The aim is to ensure legibility for the reader.
In the same way, in braille, we want to ensure that the braille is unambiguous (RUEB 1.2.2). RUEB 1.2.3 states that "the primary transcribing rule is to produce braille that, when read, yields exactly the original print text (apart from purely ornamental aspects)". In maths, "spacing should be used to reflect the structure of the mathematics" (GTM 1.1.1).
GTM 9.3 was written to illustrate how spacing of function names can be used to remove ambiguity when dealing with function names that are unspaced in print (or where the spacing is uncertain, as with half spaces). It is only when the function names are unspaced that there is possible ambiguity. If print uses spaces to set them apart it is correct to do so in braille as well. The resulting braille will not be ambiguous in any way.
They concluded by saying that removing the blank spaces when they are clearly shown in print doesn't affect the reader's ability to use the braille but is does deviate from the preferred method of following print.
Hope this helps.