@exe_child_of(son:exe, ancestor:exe)
@exe_child_of(son:exe, ancestor:proc)
@exe_child_of(son:exe, ancestor:string)


returns true if son is a descendent of ancestor. Otherwise a false value is returned.

The first argument must be a live exe. The second argument specifies the ancestor:

• by an exe;

• or by a proc value, meaning that son has been launched directly or indirectly from one instance of the proc;

• or by a string which is the label of a compound action of which one of the instances has launched son.

An is returned in case of problem (the second argument is a dead exe or is not a valid proc value).

An exe is considered as a child of itself. Thus,

      @exe_child_of(ex, ex)


returns true if exis a live exe.

The child relation between the son and the ancestor is not necessarily direct: a process $P$ that is spanned by a loop triggered by a whenever in a group $G$ is a child of $G$ (in pedantic terms, the child relation is the reflexive-transitive closure of the relation defined by the function @exe_parent).

See also @exe_parent, the special variables $MYSELF and $THISOBJ.