Metamath Proof Explorer


Theorem fun11uni

Description: The union of a chain (with respect to inclusion) of one-to-one functions is a one-to-one function. (Contributed by NM, 11-Aug-2004)

Ref Expression
Assertion fun11uni fAFunfFunf-1gAfggfFunAFunA-1

Proof

Step Hyp Ref Expression
1 simpl FunfFunf-1Funf
2 1 anim1i FunfFunf-1gAfggfFunfgAfggf
3 2 ralimi fAFunfFunf-1gAfggffAFunfgAfggf
4 fununi fAFunfgAfggfFunA
5 3 4 syl fAFunfFunf-1gAfggfFunA
6 simpr FunfFunf-1Funf-1
7 6 anim1i FunfFunf-1gAfggfFunf-1gAfggf
8 7 ralimi fAFunfFunf-1gAfggffAFunf-1gAfggf
9 funcnvuni fAFunf-1gAfggfFunA-1
10 8 9 syl fAFunfFunf-1gAfggfFunA-1
11 5 10 jca fAFunfFunf-1gAfggfFunAFunA-1