Theorem bj-1upleq

Description: Substitution property for (| - |) . (Contributed by BJ, 6-Apr-2019)

	Ref	Expression
Assertion	bj-1upleq	$$⊢A=B\to ⦅A⦆=⦅B⦆$$

Proof

Step	Hyp	Ref	Expression
1		bj-xtageq	$$⊢A=B\to \left\{\varnothing \right\}\times tagA=\left\{\varnothing \right\}\times tagB$$
2		df-bj-1upl	$$⊢⦅A⦆=\left\{\varnothing \right\}\times tagA$$
3		df-bj-1upl	$$⊢⦅B⦆=\left\{\varnothing \right\}\times tagB$$
4	1 2 3	3eqtr4g	$$⊢A=B\to ⦅A⦆=⦅B⦆$$