top_level_navigation.gram
This example ABNF grammar recognizes a small set of global navigation commands and maps each to an application directive using semantic interpretation. Saying “go back” returns APPLICATION_BACK, “main menu” returns APPLICATION_TOP, and “goodbye”, “quit”, or “exit” returns APPLICATION_EXIT. A grammar like this is typically kept active across every state of an application, so callers can navigate or exit from anywhere rather than only at specific prompts.
Example
| #ABNF 1.0; mode voice; language en-US; tag-format <semantics/1.0>; root $directive; $directive = (go back) {out = "APPLICATION_BACK"} | (main menu) {out = "APPLICATION_TOP"} | (goodbye | quit | exit) {out = "APPLICATION_EXIT"}; |