Transfer function Memes

The ultimate engineer's passive-aggressive mug! That diagram is a control systems feedback loop saying "If I wanted your input F(s), it would be factored into my system." The transfer function shows that input A(s) goes through controller G(s) to produce output X(s), with feedback H(s) creating signal B(s) - but there's no pathway for external input F(s) to influence the system! It's basically the mathematical way of saying "nobody asked for your opinion." Engineers will silently sip from this during meetings while their colleagues ramble on with unsolicited advice.