>In mathematics, Richardson's theorem establishes the undecidability of the equality of real numbers defined by expressions involving integers, π, ln ⁡ 2 , {\di

>In mathematics, Richardson's theorem establishes the undecidability of the equality of real numbers defined by expressions involving integers, π, ln ⁡ 2 , {\displaystyle \ln 2,} and exponential and sine functions. It was proved in 1968 by mathematician and computer scientist Daniel Richardson of the University of Bath. https://en.wikipedia.org/wiki/Richardson%27s_theorem https://en.wikipedia.org/wiki/Richardson%27s_theorem