Issue #1958538 by robertwb, rivimey, MustangGB, dawehner, DamienMcKenna, Joanna_Kisaakye, darrenwh, merlinofchaos, damiankloip, yugasa, izmeez, veroniqueg, japerry, zenimagine, joelpittet, zterry95, kebne, draenen, mgifford, Renrhaf, stephaniemoore, mautumn, howto: Improve math expression engine