BigFloat Precision Floating Point
GNU MPFR GNU Multiple Precision Arithmetic Library algebra accurac pari qd
https://gmplib.org/
The GNU Multiple Precision Arithmetic Library
High-Precision Software Directory
https://www.davidhbailey.com/dhbsoftware/
GNU Multiple Precision Arithmetic Library
https://zh.wikipedia.org/wiki/GNU%E5%A4%9A%E9%87%8D%E7%B2%BE%E5%BA%A6%E8%BF%90%E7%AE%97%E5%BA%93
https://en.wikipedia.org/wiki/List_of_arbitrary-precision_arithmetic_software
algebra Precision Floating Point regular expression calculator
https://www.codeproject.com/Articles/298374/Basic-mathematical-expression-evaluator
http://www.blackbeltcoder.com/Articles/algorithms/a-c-expression-evaluator
