4(5) yields NaN instead of 20

[KeronCyst]

Multiplication is implicit when an open parenthesis symbol is surrounded by numbers.

[Yet-Zio]

The calculator uses mXparser for evaluating expressions, which currently requires explicit multiplication 4*(5) instead of implicit multiplication 4(5). This behavior is due to how mXparser interprets expressions. A future update will add support for implicit multiplication, allowing 4(5) to work as expected. Thank you.

Also, newer versions of mXparser do support implicit multiplication, but they cannot be used because version 5.0 and above follow a dual-license model with terms that are incompatible with F-Droid and FOSS in general.