Theorem wleo 387

Description: L.e. absorption. (Contributed by NM, 27-Sep-1997.)

Assertion

Ref	Expression
wleo	(a ≤2 (a ∪ b)) = 1

Proof of Theorem wleo

Step	Hyp	Ref	Expression
1		wa5c 201	. 2 ((a ∩ (a ∪ b)) ≡ a) = 1
2	1	wdf2le1 385	1 (a ≤2 (a ∪ b)) = 1

Syntax hints:   = wb 1   ∪ wo 6  1wt 8   ≤₂ wle2 10

This theorem was proved from axioms:  ax-a1 30  ax-a2 31  ax-a3 32  ax-a4 33  ax-a5 34  ax-r1 35  ax-r2 36  ax-r4 37  ax-r5 38  ax-wom 361

This theorem depends on definitions:  df-b 39  df-a 40  df-t 41  df-f 42  df-i1 44  df-i2 45  df-le 129  df-le1 130  df-le2 131

This theorem is referenced by:  wledio  406  wcomorr  412  wlem14  430  ska4  433