Description: Define poset meet. (Contributed by NM, 12-Sep-2011) (Revised by NM, 8-Sep-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-meet | |- meet = ( p e. _V |-> { <. <. x , y >. , z >. | { x , y } ( glb ` p ) z } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | cmee | |- meet | |
| 1 | vp | |- p | |
| 2 | cvv | |- _V | |
| 3 | vx | |- x | |
| 4 | vy | |- y | |
| 5 | vz | |- z | |
| 6 | 3 | cv | |- x | 
| 7 | 4 | cv | |- y | 
| 8 | 6 7 | cpr |  |-  { x , y } | 
| 9 | cglb | |- glb | |
| 10 | 1 | cv | |- p | 
| 11 | 10 9 | cfv | |- ( glb ` p ) | 
| 12 | 5 | cv | |- z | 
| 13 | 8 12 11 | wbr |  |-  { x , y } ( glb ` p ) z | 
| 14 | 13 3 4 5 | coprab |  |-  { <. <. x , y >. , z >. | { x , y } ( glb ` p ) z } | 
| 15 | 1 2 14 | cmpt |  |-  ( p e. _V |-> { <. <. x , y >. , z >. | { x , y } ( glb ` p ) z } ) | 
| 16 | 0 15 | wceq |  |-  meet = ( p e. _V |-> { <. <. x , y >. , z >. | { x , y } ( glb ` p ) z } ) |