Abhyankar's inequality is an inequality involving extensions of valued fields in algebra, introduced by Abhyankar (1956).
If K/k is an extension of valued fields, then Abhyankar's inequality states that the transcendence degree of K/k is at least the transcendence degree of the residue field extension plus the Q-rank of the quotient of the valuation groups.
References
Abhyankar's inequality Wikipedia(Text) CC BY-SA