Implemented `VARMNU`, `NUM.IN` and `ALP.IN` system flags. Fixed possible crash of `CLP`, `Wp`, and matrix division; issues of `tan` in Multπ mode, `KEYG`/`KEYX`, `DECOMP`, `M.LU`; complex matrix subtraction, eigenpairs, power, and beta function; cube root with `FASTFN` set, `yPx` and `yCx`, special cases of `lnΓ`, `gd`, `P→R`, and `DECOMP`.