In reply to:

"That which has been raveled cannot be unraveled."

Even if ravel and unravel were opposites, it wouldn't make sense.


even if??
unravel v. 1. trans. To take out of a ravelled, tangled, or intertwined condition; to disentangle

<shrugs>

[yet another crossthread] actually®, *one of the senses of ravel is to unravel, yet another enantiodromic word!