Thank you, that was it!
On Monday, May 6, 2019 at 3:11:54 AM UTC+2, Leslie Lamport wrote:
You are apparently running the Java program TLA.java. That takes as input a TLA module and produces a typeset version of that module. You want to run the program TeX.java. That program takes a LaTeX file containing TLA+ formulas that appear in "tla" environments. It writes a new version of that file in which, after each such environment, it adds a "tlatex" environment (replacing any existing one) that produces the typeset version of those TLA+ formulas. The LaTeX file should use the tlatex package.
Leslie