Extraction of annotations from free text using tries

One or more tangible, machine-readable media storing processor-executable routines, wherein the processor-executable routines, when executed by a processor, cause acts to be performed comprising:

• processing a text string using a trie, wherein a number of skips are defined for processing the trie so that deviations within the text string relative to the trie up to the number of skips are allowed without falling off the trie, wherein an output of processing the text string using the trie comprises a plurality of phrases each having a respective interval;
• generating a graph based on the output, wherein the graph comprises:
• a respective node for each phrase and associated interval;
• a respective edge between each pair of non-intersecting nodes;
• determining a clique providing maximal coverage of the text string based on the graph;
• and
• determining or outputting one or more phrases corresponding to the clique as parsed phrases for the text string.

A method for selecting a subset of phrases from among a plurality of phrases, comprising:

• generating a graph comprising:
• a respective node for each phrase of the plurality of phrases, wherein each node has a corresponding interval based on the phrase corresponding to the respective node;
• a respective edge between each pair of non-intersecting nodes;
• and
• one or more cliques, wherein each clique corresponds to one or more inter-connected and non-overlapping nodes;
• determining a respective clique of the one or more cliques that provides maximal coverage of a text string comprising the plurality of phrases;
• and
• outputting a respective code corresponding to each node of the respective clique, wherein each node of the respective clique is associated with a respective phrase of the plurality of phrases.