Rule

Rule is a slide-rule-based esoteric programming language by User:Rdococ.

Overview
Rule's main esoteric gimmick is that it operates on a slide rule with multiple scales.

The S and T parameters can be one of these scales:

There is one register,, which stores the value of SREAD.

Multiplication
Multiplication is simple: SLIDE D L I 1 ; Asks for input, and slides input so that it matches with L's 1. SLIDE E L I 1 ; Ditto. SREAD D L 1 ; Reads D's number where L is at 1. thus, D's value. SLIDE B A 1 R ; Slides the rule so that B's 1 matches A's R, which is D. SREAD E L 1 ; Reads E's number into the register. SREAD A B R ; Reads A's number where B is at R (E)'s value, and stores it in R. OUT ; Outputs the result.

Actually, you could simplify it further: SLIDE B A 1 I ; Rather than sliding it into D first, ask for it directly here. SREAD A B I ; Ditto. OUT

Squaration
Squaring could not be simpler: SLIDE D L I 1 SREAD D L 1 ; Reads D's number. SREAD A C R ; Reads A's number where C is at R's value (D), and stores in R. OUT

Actually, I was wrong, it can be simpler: SREAD A C I ; Reads A's number where C is at I's value, and stores in R. OUT