Semantics in a sentence

The conventional linguistic theory only considers syntactic analyses. In this approach, the comprehension of syntactic elements obtained in the analysis process and their composed semantics as a whole for the sentence are overlooked. This may work to some extent for human comprehension of simple sentences. However, it is not only an incomplete process for human readers to deal with complex sentences, but also an inexplicit intermediate result for machines comprehension.

Therefore, a closed loop in sentence comprehension requires two additional steps beyond syntactic analysis, which are semantic analysis on the syntactic elements, and semantic synthesis with the terminal semantics of the syntactic elements [Wang and Berwick, 2012]. Modern technologies in computational linguistics and compiler theories have proven that these three steps are necessary for machine-based natural language processing.