A computer with a register file, but without PUSH and POP instructions, is to be used to i...

A computer with a register file, but without PUSH and POP instructions, is to be used to implement a stack. The computer does have the following register indirect addressing modes:

Register indirect + increment:

Decrement + register indirect:

Show how these instructions can be used to provide the equivalent of PUSH and POP by using the instructions and register R6 as the stack pointer.