# Effects of Equivalency and Interaction with COMMON Statements

When you make an element of one array equivalent to an element of another array, the EQUIVALENCE statement also sets equivalences between the other elements of the two arrays.

When you make one character substring equivalent to another character substring, the EQUIVALENCE statement also sets associations between the other corresponding characters in the character entities.

A common block can extend beyond its original boundaries if variables or arrays are associated with entities stored in the common block. However, a common block can only extend beyond its last element; the extended portion cannot precede the first element in the block.

COMMON and EQUIVALENCE are obsolescent language features in Standard Fortran.

For more information, see the topics in this section.

Parent topic: Specification Statements

- Make Arrays Equivalent
- Make Substrings Equivalent
- EQUIVALENCE and COMMON Interaction