不等式

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.

等 = ⺮ + 寺 : Inside of the engine, Don Quixote is praying in front of a Buddhist shrine. He brought a bamboo stick as offer, and he lighted it at the very top. Now he's waiting for the stick to burn down so he can go home. However, the stick is very long: Don Quixote will have to wait for a long time.

式 = 工 + 弋 : I'll use a specific style as mnemonic symbol: 哥特式, gothic.

Sherlock Holmes and the goth are celebrating a Viking festival in the space station's bathroom. They don't have trunks to throw around, so they use a steel beam. They also celebrate by practising archery. In zero gravity it is easy for them to set one world record after the next.