You go for a job as a computer architecture designer. At your interview, you tell the panel that you have some real neat ideas for some cool processors. For example, you have an instruction that can set an individual bit in memory. The format of your instruction is 

This instruction sets a bit in memory located rO plus rl bits from the word address whose address is given by the contents of memory location r2, plus the contents of register r3, plus the contents of register r4, and shifted left by register r5 plus the constant n.

You don't get the job. Why?  

BITSET r0, r1, [(r2), r3, r4 LSR r5, #n]