This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: If a point is in a half-open range, the next point is in the closed range. (Contributed by Stefan O'Rear, 23-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | fzofzp1 | |- ( C e. ( A ..^ B ) -> ( C + 1 ) e. ( A ... B ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elfzoel1 | |- ( C e. ( A ..^ B ) -> A e. ZZ ) |
|
| 2 | uzid | |- ( A e. ZZ -> A e. ( ZZ>= ` A ) ) |
|
| 3 | peano2uz | |- ( A e. ( ZZ>= ` A ) -> ( A + 1 ) e. ( ZZ>= ` A ) ) |
|
| 4 | fzoss1 | |- ( ( A + 1 ) e. ( ZZ>= ` A ) -> ( ( A + 1 ) ..^ ( B + 1 ) ) C_ ( A ..^ ( B + 1 ) ) ) |
|
| 5 | 1 2 3 4 | 4syl | |- ( C e. ( A ..^ B ) -> ( ( A + 1 ) ..^ ( B + 1 ) ) C_ ( A ..^ ( B + 1 ) ) ) |
| 6 | 1z | |- 1 e. ZZ |
|
| 7 | fzoaddel | |- ( ( C e. ( A ..^ B ) /\ 1 e. ZZ ) -> ( C + 1 ) e. ( ( A + 1 ) ..^ ( B + 1 ) ) ) |
|
| 8 | 6 7 | mpan2 | |- ( C e. ( A ..^ B ) -> ( C + 1 ) e. ( ( A + 1 ) ..^ ( B + 1 ) ) ) |
| 9 | 5 8 | sseldd | |- ( C e. ( A ..^ B ) -> ( C + 1 ) e. ( A ..^ ( B + 1 ) ) ) |
| 10 | elfzoel2 | |- ( C e. ( A ..^ B ) -> B e. ZZ ) |
|
| 11 | fzval3 | |- ( B e. ZZ -> ( A ... B ) = ( A ..^ ( B + 1 ) ) ) |
|
| 12 | 10 11 | syl | |- ( C e. ( A ..^ B ) -> ( A ... B ) = ( A ..^ ( B + 1 ) ) ) |
| 13 | 9 12 | eleqtrrd | |- ( C e. ( A ..^ B ) -> ( C + 1 ) e. ( A ... B ) ) |