<.foolbox_pipe          This operator is used together with 'rewrites'
                        to transform a function after it is defined and
                        before it is assigned to a name.
[.foolbox_rewrite_spec
                        Provide list of rewrite transformations.
add_call_callback       Add a function-specific callback to the call
                        callbacks.
add_topdown_callback    Add a function-specific callback to the
                        top-down callbacks.
annotate_assigned_symbols_callbacks
                        Put attribute "assigned_symbols" on expressions
                        bottom-up
annotate_bound_symbols_in_function
                        Annotate sub-expressions with variables bound
                        in their scope.
annotate_bound_variables_callbacks
                        Propagate parameters and local variables
                        top-down to assign attribute "bound" to all
                        call expressions.
collect_assigned_symbols_in_expression
                        Extracts all the symbols that appear on the
                        left-hand side of an assignment.
collect_from_args       Collect attributes set in the arguments to a
                        call expression.
depth_first_analyse_expr
                        Analyse an expression.
depth_first_analyse_function
                        Analyse the body of function.
depth_first_rewrite_expr
                        Transform an expression.
depth_first_rewrite_function
                        Transform the body of function.
identity_rewrite_callback
                        A callback that does not do any transformation.
make_with_callback      Create a function for setting callbacks.
merge_bottomup          Merge the results of several bottomup results.
nop_topdown_callback    Top-down analysis callback.
remove_formal           Remove a parameter from the formal parameters
                        of a function.
remove_formal_          Remove a parameter from the formal parameters
                        of a function.
rewrite_callbacks       Default expression-transformation callbacks.
rewrite_with            Functions for applying a sequence of rewrites.
rewrites                Object for setting up a transformation pipeline
                        when defining functions
warning_flags           Collection of warning flags used when
                        traversing expressions.
