Description: Closure law for the extended division. (Contributed by Thierry Arnoux, 15-Mar-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xdivcl | |- ( ( A e. RR* /\ B e. RR /\ B =/= 0 ) -> ( A /e B ) e. RR* )  | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simp1 | |- ( ( A e. RR* /\ B e. RR /\ B =/= 0 ) -> A e. RR* )  | 
						|
| 2 | simp2 | |- ( ( A e. RR* /\ B e. RR /\ B =/= 0 ) -> B e. RR )  | 
						|
| 3 | simp3 | |- ( ( A e. RR* /\ B e. RR /\ B =/= 0 ) -> B =/= 0 )  | 
						|
| 4 | 1 2 3 | xdivcld | |- ( ( A e. RR* /\ B e. RR /\ B =/= 0 ) -> ( A /e B ) e. RR* )  |