Description: Define the set of closed-below, open-above intervals of extended reals. (Contributed by NM, 24-Dec-2006)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-ico | |- [,) = ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z < y ) } ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cico | |- [,) |
|
| 1 | vx | |- x |
|
| 2 | cxr | |- RR* |
|
| 3 | vy | |- y |
|
| 4 | vz | |- z |
|
| 5 | 1 | cv | |- x |
| 6 | cle | |- <_ |
|
| 7 | 4 | cv | |- z |
| 8 | 5 7 6 | wbr | |- x <_ z |
| 9 | clt | |- < |
|
| 10 | 3 | cv | |- y |
| 11 | 7 10 9 | wbr | |- z < y |
| 12 | 8 11 | wa | |- ( x <_ z /\ z < y ) |
| 13 | 12 4 2 | crab | |- { z e. RR* | ( x <_ z /\ z < y ) } |
| 14 | 1 3 2 2 13 | cmpo | |- ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z < y ) } ) |
| 15 | 0 14 | wceq | |- [,) = ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z < y ) } ) |