Generic term traversal operators support te definition of Generic term traversal strategies like topdown and bottomup. Operators available in Stratego are:

• one applies a strategy to one direct subterm.
• some applies a strategy to as much as possible, but a least one, direct subterms.
• all applies a strategy to all direct subterms of the subject term.

The generic term traversal operators are built-in: they are not defined in Stratego itself. It is however possible to define them in Stratego with even more primitive strategies.