T-rule

T-rules, or transformation rules, are rules that alter the state of the machine. As describe in the UNL Grammar Specs, they follow the general formalism:

<INITIAL STATE>:=<FINAL STATE>;

And may be classified according to the type of modification that they promote:

• LL, or list-to-list, operates over nodes in list tructures (as natural language sentences)
• TT, or tree-to-tree, operates over nodes in tree structures (as syntactic representations)
• NN, or network-to-network, operates over nodes in network structures (as semantic representations)
• LT, or list-to-tree, converts lists into trees
• TL, or tree-to-list, converts trees into lists
• TN, or tree-to-networks, converts trees into networks
• NT, or network-to-trees, converts networks into trees