Table 1.

Binary preference relationships between two alternatives a,b (adapted from Figueira et al., 2013).

Relationship	Notation	Description
Indifference	$aIb$	no difference in preference between alternatives a and b
Strict preference	$aPb$	alternative a is strictly preferred to b
Fuzzy preference	a⧘P⧘b	the degree to which alternative a is preferred to b is distinguished by some function reflecting ambiguity in preferences over uncertain outcomes
Incomparable	$aRb$	special situation in which a preference relationship cannot be determined without additional information