Nuprl Lemma : rmul_comm
∀[a,b:ℝ].  ((a * b) = (b * a))
Proof
Definitions occuring in Statement : 
req: x = y
, 
rmul: a * b
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
req-iff-bdd-diff, 
rmul_wf, 
req_witness, 
real_wf, 
reg-seq-mul_wf, 
bdd-diff_weakening, 
equal_wf, 
squash_wf, 
true_wf, 
nat_plus_wf, 
reg-seq-mul-comm, 
iff_weakening_equal, 
bdd-diff_functionality, 
rmul-bdd-diff-reg-seq-mul
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
productElimination, 
independent_isectElimination, 
independent_functionElimination, 
sqequalRule, 
isect_memberEquality, 
because_Cache, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
dependent_functionElimination, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
functionEquality, 
intEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}[a,b:\mBbbR{}].    ((a  *  b)  =  (b  *  a))
Date html generated:
2017_10_02-PM-07_15_36
Last ObjectModification:
2017_07_28-AM-07_20_34
Theory : reals
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