BoolResult returns a Result that is either Equal or not Equal.

Difference reports whether two lists of lengths nx and ny are equal given the definition of equality provided as f.

Identity indicates that a symbol pair is identical in both list X and Y.

Modified indicates that a symbol pair is a modification of each other.

UniqueX indicates that a symbol only exists in X and not Y.

UniqueY indicates that a symbol only exists in Y and not X.

Result is the result of comparison.

EditScript represents the series of differences between two lists.

EditType represents a single operation within an edit-script.

EqualFunc reports whether the symbols at indexes ix and iy are equal.