F-PUT-GLOBAL.html -- ACL2 Version 6.3

### F-PUT-GLOBAL

assign to a global variable in `state`

    Major Section:  ACL2-BUILT-INS

    Examples:
    (f-put-global 'x (expt 2 10) state)
    (f-put-global 'a (aset1 'ascii-map-array (@ a) 66 'Upper-case-B) state)

    General Form:
    (f-put-global (quote symbol) term state)

where `symbol` is any symbol (with certain enforced exclusions to avoid overwriting ACL2 system ``globals'') and `term` is any ACL2 term that could be evaluated at the top-level. `F-put-global` evaluates the term, stores the result as the value of the given symbol in the `global-table` of `state`, and returns the new `state`. (Note: the actual implementation of the storage of this value is much more efficient than this discussion of the logic might suggest.)

The macro `assign` is closely related to `f-put-global`: `(assign var val)` macroexpands to `(f-put-global 'var val state)`.

The macros `@` and `f-get-global` give convenient access to the value of such globals. The `:``ubt` operation has no effect on the `global-table` of `state`. Thus, you may use these globals to hang onto useful data structures even though you may undo back past where you computed and saved them.