definition
This definition's A_Set of A_Stylers. A module must not define more than one styler on the same A_Definition.
When styling a phrase, all applicable definitions are consulted, filtering by which definitions are visible to the current module, and which definitions contain at least one styler visible to the current module. These are placed in a LookupTree (easily cached in the AvailLoader), and the phrase's argument phrases are used to identify the most specific relevant definition. Once the definition is chosen, the visible modules that have a styler for that definition are selected (there must be at least one, otherwise the definition would have been excluded from the lookup tree). If there is a styler from an ancestor module that dominates (i.e., all other applicable modules are themselves ancestors of it), then the styler from that module is used. Otherwise a special conflict styler will be used to bring attention to the collision.