Nuprl Lemma : bor_ff_simp
∀[u:𝔹]. u ∨bff = u
Proof
Definitions occuring in Statement : 
bor: p ∨bq
, 
bfalse: ff
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
bor: p ∨bq
, 
bool: 𝔹
, 
unit: Unit
, 
member: t ∈ T
, 
it: ⋅
, 
btrue: tt
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
Lemmas referenced : 
btrue_wf, 
bfalse_wf, 
bool_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
unionElimination, 
thin, 
equalityElimination, 
introduction, 
extract_by_obid, 
hypothesis, 
Error :universeIsType
Latex:
\mforall{}[u:\mBbbB{}].  u  \mvee{}\msubb{}ff  =  u
Date html generated:
2019_06_20-AM-11_31_00
Last ObjectModification:
2018_09_26-AM-11_14_52
Theory : bool_1
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