Theorem inundifss 3602

Description: The intersection and class difference of a class with another class are contained in the original class. In classical logic we'd be able to make a stronger statement: that everything in the original class is in the intersection or the difference (that is, this theorem would be equality rather than subset). (Contributed by Jim Kingdon, 4-Aug-2018.)

Assertion

Ref	Expression
inundifss	|- ( ( A i^i B ) u. ( A \ B ) ) C_ A

Proof of Theorem inundifss

Step	Hyp	Ref	Expression
1		inss1 3451	. 2 |- ( A i^i B ) C_ A
2		difss 3355	. 2 |- ( A \ B ) C_ A
3	1, 2	unssi 3404	1 |- ( ( A i^i B ) u. ( A \ B ) ) C_ A

Syntax hints:   \ cdif 3217   u. cun 3218   i^i cin 3219   C_ wss 3220

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-v 2823  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233

This theorem is referenced by:  resasplitss  5564