An alternative to union within a sequence is the branch non-terminal ("branch"). Like union, branch joins a parent and child node. Wrapped by opening and closing parenthesis terminals ("(" and ")" respectively), branch encodes a sequence that may or may not be bonded to its parent. Bonding occurs if the bond non-terminal is included. Alternatively, the sequence will not be bonded if the dot non-terminal (".") appears. If neither bond nor gap are present, parent and child are connected through an elided bond.