Made built-in functions work for the first time. (#2916)
Made built-in functions work for the first time. (#2916)

Made built-in functions work for the first time.

Co-authored-by: Dr. Johannes Ruscheinski <8b91ca2620a71d9efc2b0f7bb40f65ff66bc02b1@uni-tuebingen.de>
ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools