Btukfyl

documentclasslistfiles[varwidth]{standalone}

usepackage{lmodern}

usepackage{bm}

usepackage{amsmath, amsthm, amssymb, amsfonts, amstext}



begin{document}fontsize{30}{36}selectfont

Let $a$ be a symbol.

end{document}

The result is:

Let $a$ beasymbol.

I'm not sure how to not ignore spaces in the document.

This is pdfTeX, Version 3.14159265-2.6-1.40.18 (MiKTeX 2.9.6500 64-bit) (preloaded format=latex 2017.10.12)  29 NOV 2018 20:50 entering extended mode

**./latex_input.tex (latex_input.tex LaTeX2e <2017-04-15> Babel <3.10> and hyphenation patterns for 75 language(s) loaded. ! TeX capacity exceeded, sorry [input stack size=5000]. listfiles ->let listfiles 

                             relax def @listfiles ##1##2##3##4##5##6##7##... l.1 documentclasslistfiles[varwidth]

                                      {standalone} If you really absolutely need more capacity, you can ask a wizard to enlarge me.



  Here is how much of TeX's memory you used:  7 strings out of 493324  203 string characters out of 3146842  53645 words of memory out of 3000000  3645 multiletter control sequences out of 15000+200000  3640 words of font info for 14 fonts, out of 3000000 for 9000  1141 hyphenation exceptions out of 8191  5000i,0n,6p,67b,8s stack positions out of 5000i,500n,10000p,200000b,50000s No pages of output.