Metamath Proof Explorer


Theorem chsleji

Description: Subspace sum is smaller than subspace join. Remark in Kalmbach p. 65. (Contributed by NM, 17-Oct-1999) (New usage is discouraged.)

Ref Expression
Hypotheses ch0le.1 AC
chjcl.2 BC
Assertion chsleji A+BAB

Proof

Step Hyp Ref Expression
1 ch0le.1 AC
2 chjcl.2 BC
3 1 chshii AS
4 2 chshii BS
5 3 4 shsleji A+BAB