unary operator: primorial a#

The product of the first pi(a) prime numbers p_{i} starting with p_{1 }= 2, where pi(a) is the (not-greater-than-)prime-counting function. Not strictly monotonically increasing unless a=p_{j} for positive integers j.

- ne'o'o
*(exp!)* - mekso quaternary operator – Pochhammer symbol: with/for input (X
_{1, X}, this word/function outputs \prod_{k }= 0^X_{2 - 1 (X}; by default, X_{4 }= 1 unless explicitly defined otherwise.