Maximal Distance. The property of Maximal Distance is an interesting generalization that holds in the theory. Axiom IV (Maximal Distance)17 If x corresponds to y then x differs from y for one and only one property.18 (xiii) For instance, I/O-Correspondence is instantiated between root nodes in the input and root nodes in the output. The elements differ for one and only one property: I or O. For ℛI-O, I have: I = {x | x ∈ ⊙ ∧ x ∈ I} O = {x | x ∈ ⊙ ∧ x ∈ O} Likewise, for two elements to be in φ-Correspondence, they must differ for only one and only one property: headedness. A head feature node [+sib] cannot correspond to a dependent [−sib] or [+voc], because the property difference would be higher than one. 17 In fact, this axiom expresses both the maximal and minimal distance. 18 The minimal distance is one since the relation is heterogeneous. The axiom of Maximal Distance provides an important piece of phonological insight. Correspondence is empirically manifested in input/output domain phenomena, in reduplication, and in agreement. Although apparently different, all these processes can be traced back to one requirement: correspondence is about wanting similar elements to be maximally identical (within the limits imposed by the axioms). The Maximal Distance axiom ensures that only elements that are sufficiently similar can be in correspondence. The axiom intuitively extends to other types of correspondence relations. In B/R- Correspondence, the elements in correspondence are root nodes in the output, and the property that differs concern whether the element is in the reduplicant or not. In Tone/TBU-Correspondence, both elements are in the output, but they differ for their derivational property (tones vs. TBUs).19
Maximal Distance. The property of Maximal Distance is an interesting generalization that holds in the theory. Axiom IV (Maximal Distance)17 If x corresponds to y then x differs from y for one and only one property.18 (xiii) For instance, I/O-Correspondence is instantiated between root nodes in the input and root nodes in the output. The elements differ for one and only one property: I or O. For ℛI-O, I have: I = {x | x ∈ ⊙ ∧ x ∈ I} O = {x | x ∈ ⊙ ∧ x ∈ O} Likewise, for two elements to be in φ-Correspondence, they must differ for only one and only one property: headedness. A head feature node [+sib] cannot correspond to a dependent [−sib] or [+voc], because the property difference would be higher than one. The axiom of Maximal Distance provides an important piece of phonological insight. Correspondence is empirically manifested in input/output domain phenomena, in reduplication, and in agreement. Although apparently different, all these processes can be traced back to one requirement: correspondence is about wanting similar elements to be maximally identical (within the limits imposed by the axioms). The Maximal Distance axiom ensures that only elements that are sufficiently similar can be in correspondence. 17 In fact, this axiom expresses both the maximal and minimal distance.
