code: public char match(String str1, String str2) {
          invocationCount++;
          char rel = IMappingElement.IDK;
  
          if (str1 == null || str2 == null) {
              rel = IMappingElement.IDK;
          } else {
              if ((str1.length() > 3) && (str2.length() > 3)) {
                  if (str1.startsWith(str2)) {
                      if (str1.contains(" ")) {
                          rel = IMappingElement.LESS_GENERAL;
                      } else {
                          rel = IMappingElement.EQUIVALENCE;
                      }
                  } else {
                      if (str2.startsWith(str1)) {
                          if (str2.contains(" ")) {
                              rel = IMappingElement.MORE_GENERAL;
                          } else {
                              rel = IMappingElement.EQUIVALENCE;
                          }
                      }
                  }
              }//if ((str1.length() > 3) && (str2.length() > 3)) {
          }
  
          if (rel != IMappingElement.IDK) {
              relCount++;
              addCase(str1, str2, rel);
          }
          return rel;
      }
docs: Computes the relation with prefix matcher.
  
  @param str1 the source string
  @param str2 the target string
  @return synonym, more general, less general or IDK relation