Description: Closure law for subtraction of reals. (Contributed by NM, 17-Jan-1997) (Revised by Mario Carneiro, 27-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypotheses | renegcl.1 | |
|
resubcl.2 | |
||
Assertion | resubcli | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | renegcl.1 | |
|
2 | resubcl.2 | |
|
3 | 1 | recni | |
4 | 2 | recni | |
5 | negsub | |
|
6 | 3 4 5 | mp2an | |
7 | 2 | renegcli | |
8 | 1 7 | readdcli | |
9 | 6 8 | eqeltrri | |