3. The computer-readable, non-transitory medium according to claim 2 , wherein the process further includes: generating the first conceptual structure based upon the first character string; and generating the second conceptual structure based upon the second character string.
2. The computer-readable, non-transitory medium according to claim 1 , wherein the process further includes: acquiring a first conceptual structure that has a first conceptual code as a first element corresponding to a first word in the first character string, the first element being associated based upon the semantic attribute or a location of the first word, and a second conceptual structure having a second conceptual code as a second element corresponding to a second word in the second character string, the second element being associated based upon the semantic attribute or a location of the second word; and comparing the first conceptual code and the second conceptual code of corresponding elements between the first conceptual structure and the second conceptual structure, the first conceptual structure and the second conceptual structure being set up in common according to a semantic domain that a whole length of the first character string and a whole length of the second character string have in common.