Metamath Proof Explorer


Theorem dochkrsm

Description: The subspace sum of a closed subspace and a kernel orthocomplement is closed. ( djhlsmcl can be used to convert sum to join.) (Contributed by NM, 29-Jan-2015)

Ref Expression
Hypotheses dochkrsm.h H=LHypK
dochkrsm.i I=DIsoHKW
dochkrsm.o ˙=ocHKW
dochkrsm.u U=DVecHKW
dochkrsm.p ˙=LSSumU
dochkrsm.f F=LFnlU
dochkrsm.l L=LKerU
dochkrsm.k φKHLWH
dochkrsm.x φXranI
dochkrsm.g φGF
Assertion dochkrsm φX˙˙LGranI

Proof

Step Hyp Ref Expression
1 dochkrsm.h H=LHypK
2 dochkrsm.i I=DIsoHKW
3 dochkrsm.o ˙=ocHKW
4 dochkrsm.u U=DVecHKW
5 dochkrsm.p ˙=LSSumU
6 dochkrsm.f F=LFnlU
7 dochkrsm.l L=LKerU
8 dochkrsm.k φKHLWH
9 dochkrsm.x φXranI
10 dochkrsm.g φGF
11 eqid LSAtomsU=LSAtomsU
12 8 adantr φ˙LGLSAtomsUKHLWH
13 9 adantr φ˙LGLSAtomsUXranI
14 simpr φ˙LGLSAtomsU˙LGLSAtomsU
15 1 2 4 5 11 12 13 14 dihsmatrn φ˙LGLSAtomsUX˙˙LGranI
16 oveq2 ˙LG=0UX˙˙LG=X˙0U
17 1 4 8 dvhlmod φULMod
18 eqid LSubSpU=LSubSpU
19 1 4 2 18 dihrnlss KHLWHXranIXLSubSpU
20 8 9 19 syl2anc φXLSubSpU
21 18 lsssubg ULModXLSubSpUXSubGrpU
22 17 20 21 syl2anc φXSubGrpU
23 eqid 0U=0U
24 23 5 lsm01 XSubGrpUX˙0U=X
25 22 24 syl φX˙0U=X
26 16 25 sylan9eqr φ˙LG=0UX˙˙LG=X
27 9 adantr φ˙LG=0UXranI
28 26 27 eqeltrd φ˙LG=0UX˙˙LGranI
29 1 3 4 23 11 6 7 8 10 dochsat0 φ˙LGLSAtomsU˙LG=0U
30 15 28 29 mpjaodan φX˙˙LGranI