AREF2.html -- ACL2 Version 6.3

### AREF2

access the elements of a 2-dimensional array

    Major Section:  ARRAYS

    Example Form:
    (aref2 'delta1 a i j)

    General Form:
    (aref2 name alist i j)

where `name` is a symbol, `alist` is a 2-dimensional array and `i` and `j` are legal indices into `alist`. This function returns the value associated with `(i . j)` in `alist`, or else the default value of the array. See arrays for details.

This function executes in virtually constant time if `alist` is in fact the ``semantic value'' associated with `name` (see arrays). When it is not, `aref2` must do a linear search through `alist`. In that case the correct answer is returned but a slow array comment is printed to the comment window. See slow-array-warning.