The theory of F-rational signature

F-signature is an important numeric invariant of singularities in positive char-acteristic that can be used to detect strong F-regularity. One would like to have a variant that rather detects F-rationality, and there are two theories that aim to fill this gap: F-rational sig-nature of Hochster and Yao and dual F-signature of Sannai. Unfortunately, several importantproperties of the original F-signature are unknown for these invariants. We find a modification of the Hochster-Yao definition that agrees with Sannai's dual F-signature and push further the united theory to achieve a completegeneralization of F-signature.