We are all very familiar with prefixes. Many times there seem to be a pair of two opposite prefixes such as pro- and con-; in- and ex-.
Often times the two prefixes that seem to be paired seem to be opposite in meaning. In- and ex- can suggest inside and outside, as in interior and exterior. However, this is one example where you can't push this too far and make it truly general: Intrude and extrude are by no means opposite.
One perhaps amusing if (hopefully) not almost sacrilegious pair might be pro-stitution and con-stitution. Hopefully that example shows that prefixes might sometimes be opposite in meaning but are not always!
