2. The computer-readable medium according to claim 1 , wherein the first requirement includes a parameter range showing the range of an element parameter that indicates properties of a graphic to be selected as a ruled line element of the ruled line and/or the range of a consolidation parameter that indicates properties of the graphic of the ruled line element to be consolidated as ruled line candidate.
2. The computer-readable medium according to claim 1 , wherein the first requirement includes a parameter range showing the range of an element parameter that indicates properties of a graphic to be selected as a ruled line element of the ruled line and/or the range of a consolidation parameter that indicates properties of the graphic of the ruled line element to be consolidated as ruled line candidate. 9. The computer-readable medium according to claim 2 , wherein the judging judges the ruled line candidate as unstable when the positional arrangement of the ruled line elements included in the ruled line candidate is not uniform.