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Description: An element not less than another is nonzero. TODO: Look for uses of necon3bd and op0le to see if this is useful elsewhere. (Contributed by NM, 5-May-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | op0le.b | |- B = ( Base ` K ) |
|
| op0le.l | |- .<_ = ( le ` K ) |
||
| op0le.z | |- .0. = ( 0. ` K ) |
||
| Assertion | opnlen0 | |- ( ( ( K e. OP /\ X e. B /\ Y e. B ) /\ -. X .<_ Y ) -> X =/= .0. ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | op0le.b | |- B = ( Base ` K ) |
|
| 2 | op0le.l | |- .<_ = ( le ` K ) |
|
| 3 | op0le.z | |- .0. = ( 0. ` K ) |
|
| 4 | 1 2 3 | op0le | |- ( ( K e. OP /\ Y e. B ) -> .0. .<_ Y ) |
| 5 | 4 | 3adant2 | |- ( ( K e. OP /\ X e. B /\ Y e. B ) -> .0. .<_ Y ) |
| 6 | breq1 | |- ( X = .0. -> ( X .<_ Y <-> .0. .<_ Y ) ) |
|
| 7 | 5 6 | syl5ibrcom | |- ( ( K e. OP /\ X e. B /\ Y e. B ) -> ( X = .0. -> X .<_ Y ) ) |
| 8 | 7 | necon3bd | |- ( ( K e. OP /\ X e. B /\ Y e. B ) -> ( -. X .<_ Y -> X =/= .0. ) ) |
| 9 | 8 | imp | |- ( ( ( K e. OP /\ X e. B /\ Y e. B ) /\ -. X .<_ Y ) -> X =/= .0. ) |