A$.5$ One Instruction Set Computer

An one instruction set computer $($OISC$)$ is an extreme form of a RISC ISA $-$ it has only $1$ instruction. In this question, consider one such machife called SUBLEQ. A SUBLEQ machine has exactly one instruction that "subtracts and branches if less than or equal to zero" $($called subleq$)$:

subleq a$,$ b$,$ c

A subleq instruction has $3$ operands, $a,b$ and $c,$ which are all memory addresses. It has the following semantic:

$)(0$

Page $5$ of $14$