Negative sets: {- 1.5, ﹣4 and two-thirds, ﹣4 and five-sevenths, ﹣3.38,} are generally signed, not 0.
Integer set: {22,0,} generally has no "."
Score settings: {﹣4 and 2/3, ﹣4 and 5/7} and scores.
Set of rational numbers: {﹣ 1.5, 7.3, ﹣4 and 2/3, 22, 0, ﹣4 and 5/7, ﹣3.38,} the numbers are clear.
Set of irrational numbers: {π,1.010010001…, 0.66…} countless.
Non-positive integer sets: {- 1.5, ﹣4 and 2/3, ﹣4 and 5/7, ﹣3.38,} are generally signed, and 0 is used.
The set of non-positive and negative numbers: {7.3, 22, 0.66, π} generally has no negative sign and 0.
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