Weakening p. pr. & vb. n. : of Weaken

Example:
What can you do to prevent Weakening eyesight?

Taxonomy
Monotonicity of entailment, Logic, free encyclopedia, inference rule, rule, non-monotonic logics, logical systems, explicit rule, search, Unsourced, states, hypotheses, assumptions, monotone, admissible, exceptions, default reasoning, hypothesis.

Defination from the web:
Weakening) Jump to: navigation, search. This article does not cite any references or sources. ... In most logics, weakening is either an inference rule or a metatheorem if the logic doesn't have an explicit rule. Notable exceptions are: ...