Nuprl Lemma : contrapos_elim2
P,Q:
. ((R:. (
R 
(
R))) 
((Q) (P)) {(P) (Q)})
Proof
Definitions occuring in Statement :
prop: ,
guard: {T},
all: x:A. B[x],
not: A,
squash: T,
implies: P Q,
or: P Q
Definitions :
all: x:A. B[x],
prop: ,
implies: P Q,
squash: T,
not: A,
guard: {T},
true: True,
member: t 
T,
false: False,
so_lambda: 
x.t[x],
or: P Q,
uall: [x:A]. B[x],
so_apply: x[s]
Lemmas :
squash_wf,
not_wf,
all_wf,
or_wf
\mforall{}P,Q:\mBbbP{}. ((\mforall{}R:\mBbbP{}. (\mdownarrow{}R \mvee{} (\mneg{}R))) {}\mRightarrow{} ((\mneg{}\mdownarrow{}Q) {}\mRightarrow{} (\mneg{}\mdownarrow{}P)) {}\mRightarrow{} \{(\mdownarrow{}P) {}\mRightarrow{} (\mdownarrow{}Q)\})
Date html generated:
2013_03_20-AM-10_48_58
Last ObjectModification:
2013_02_25-PM-06_11_38
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