:: CQC_THE2 semantic presentation

theorem Th1: :: CQC_THE2:1
for b1, b2, b3 being Element of CQC-WFF st |- b1 => (b2 => b3) holds
|- (b1 '&' b2) => b3
proof end;

theorem Th2: :: CQC_THE2:2
for b1, b2, b3 being Element of CQC-WFF st |- b1 => (b2 => b3) holds
|- (b2 '&' b1) => b3
proof end;

theorem Th3: :: CQC_THE2:3
for b1, b2, b3 being Element of CQC-WFF st |- (b1 '&' b2) => b3 holds
|- b1 => (b2 => b3)
proof end;

theorem Th4: :: CQC_THE2:4
for b1, b2, b3 being Element of CQC-WFF st |- (b1 '&' b2) => b3 holds
|- b2 => (b1 => b3)
proof end;

Lemma5: for b1, b2 being Element of CQC-WFF holds
( |- (b1 '&' b2) => b1 & |- (b1 '&' b2) => b2 )
proof end;

Lemma6: for b1, b2 being Element of CQC-WFF st |- b1 '&' b2 holds
( |- b1 & |- b2 )
proof end;

Lemma7: for b1, b2, b3 being Element of CQC-WFF st |- b1 => b2 & |- b1 => b3 holds
|- b1 => (b2 '&' b3)
proof end;

Lemma8: for b1, b2, b3, b4 being Element of CQC-WFF st |- b1 => b2 & |- b3 => b4 holds
|- (b1 'or' b3) => (b2 'or' b4)
proof end;

Lemma9: for b1, b2, b3, b4 being Element of CQC-WFF st |- b1 => b2 & |- b3 => b4 holds
|- (b1 '&' b3) => (b2 '&' b4)
proof end;

Lemma10: for b1, b2 being Element of CQC-WFF holds
( |- b1 => (b1 'or' b2) & |- b1 => (b2 'or' b1) )
proof end;

Lemma11: for b1, b2, b3 being Element of CQC-WFF st |- b1 => b2 & |- b3 => b2 holds
|- (b1 'or' b3) => b2
proof end;

Lemma12: for b1, b2 being Element of CQC-WFF st |- b1 & |- b2 holds
|- b1 '&' b2
proof end;

Lemma13: for b1, b2, b3 being Element of CQC-WFF st |- b1 => b2 holds
|- (b3 '&' b1) => (b3 '&' b2)
proof end;

Lemma14: for b1, b2, b3 being Element of CQC-WFF st |- b1 => b2 holds
|- (b1 'or' b3) => (b2 'or' b3)
proof end;

Lemma15: for b1, b2 being Element of CQC-WFF holds |- (b1 'or' b2) => (('not' b1) => b2)
proof end;

Lemma16: for b1, b2 being Element of CQC-WFF holds |- (('not' b1) => b2) => (b1 'or' b2)
proof end;

Lemma17: for b1 being Element of CQC-WFF holds |- b1 <=> b1
proof end;

Lemma18: for b1, b2 being Element of CQC-WFF holds
( ( |- b1 => b2 & |- b2 => b1 ) iff |- b1 <=> b2 )
proof end;

Lemma19: for b1, b2 being Element of CQC-WFF st |- b1 <=> b2 holds
( |- b1 iff |- b2 )
proof end;

Lemma20: for b1, b2, b3, b4 being Element of CQC-WFF st |- b1 => (b2 => b3) & |- b3 => b4 holds
|- b1 => (b2 => b4)
proof end;

theorem Th5: :: CQC_THE2:5
for b1 being QC-formula
for b2, b3 being bound_QC-variable holds
( b2 in still_not-bound_in (All b3,b1) iff ( b2 in still_not-bound_in b1 & b2 <> b3 ) )
proof end;

theorem Th6: :: CQC_THE2:6
for b1 being QC-formula
for b2, b3 being bound_QC-variable holds
( b2 in still_not-bound_in (Ex b3,b1) iff ( b2 in still_not-bound_in b1 & b2 <> b3 ) )
proof end;

theorem Th7: :: CQC_THE2:7
for b1, b2 being QC-formula
for b3 being bound_QC-variable holds
( b3 in still_not-bound_in (b1 => b2) iff ( b3 in still_not-bound_in b1 or b3 in still_not-bound_in b2 ) )
proof end;

theorem Th8: :: CQC_THE2:8
canceled;

theorem Th9: :: CQC_THE2:9
for b1, b2 being QC-formula
for b3 being bound_QC-variable holds
( b3 in still_not-bound_in (b1 '&' b2) iff ( b3 in still_not-bound_in b1 or b3 in still_not-bound_in b2 ) )
proof end;

theorem Th10: :: CQC_THE2:10
for b1, b2 being QC-formula
for b3 being bound_QC-variable holds
( b3 in still_not-bound_in (b1 'or' b2) iff ( b3 in still_not-bound_in b1 or b3 in still_not-bound_in b2 ) )
proof end;

theorem Th11: :: CQC_THE2:11
for b1 being QC-formula
for b2, b3 being bound_QC-variable holds
( not b2 in still_not-bound_in (All b2,b3,b1) & not b3 in still_not-bound_in (All b2,b3,b1) )
proof end;

theorem Th12: :: CQC_THE2:12
for b1 being QC-formula
for b2, b3 being bound_QC-variable holds
( not b2 in still_not-bound_in (Ex b2,b3,b1) & not b3 in still_not-bound_in (Ex b2,b3,b1) )
proof end;

theorem Th13: :: CQC_THE2:13
canceled;

theorem Th14: :: CQC_THE2:14
for b1, b2 being QC-formula
for b3 being bound_QC-variable holds (b1 => b2) . b3 = (b1 . b3) => (b2 . b3)
proof end;

theorem Th15: :: CQC_THE2:15
for b1, b2 being QC-formula
for b3 being bound_QC-variable holds (b1 'or' b2) . b3 = (b1 . b3) 'or' (b2 . b3)
proof end;

theorem Th16: :: CQC_THE2:16
canceled;

theorem Th17: :: CQC_THE2:17
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable st b2 <> b3 holds
(Ex b2,b1) . b3 = Ex b2,(b1 . b3)
proof end;

theorem Th18: :: CQC_THE2:18
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- b1 => (Ex b2,b1)
proof end;

theorem Th19: :: CQC_THE2:19
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable st |- b1 holds
|- Ex b2,b1
proof end;

theorem Th20: :: CQC_THE2:20
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- (All b2,b1) => (Ex b2,b1)
proof end;

theorem Th21: :: CQC_THE2:21
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable holds |- (All b2,b1) => (Ex b3,b1)
proof end;

theorem Th22: :: CQC_THE2:22
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st |- b1 => b2 & not b3 in still_not-bound_in b2 holds
|- (Ex b3,b1) => b2
proof end;

theorem Th23: :: CQC_THE2:23
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable st not b2 in still_not-bound_in b1 holds
|- (Ex b2,b1) => b1
proof end;

theorem Th24: :: CQC_THE2:24
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable st not b2 in still_not-bound_in b1 & |- Ex b2,b1 holds
|- b1
proof end;

theorem Th25: :: CQC_THE2:25
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b5 in still_not-bound_in b3 holds
|- b1 => (Ex b5,b2)
proof end;

theorem Th26: :: CQC_THE2:26
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable st |- b1 holds
|- All b2,b1
proof end;

theorem Th27: :: CQC_THE2:27
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable st not b2 in still_not-bound_in b1 holds
|- b1 => (All b2,b1)
proof end;

theorem Th28: :: CQC_THE2:28
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b4 in still_not-bound_in b3 holds
|- (All b4,b1) => b2
proof end;

theorem Th29: :: CQC_THE2:29
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable st not b2 in still_not-bound_in b1 holds
|- (All b3,b1) => (All b2,b1)
proof end;

theorem Th30: :: CQC_THE2:30
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b4 in still_not-bound_in b3 & not b5 in still_not-bound_in b1 holds
|- (All b4,b1) => (All b5,b2)
proof end;

theorem Th31: :: CQC_THE2:31
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable st not b2 in still_not-bound_in b1 holds
|- (Ex b2,b1) => (Ex b3,b1)
proof end;

theorem Th32: :: CQC_THE2:32
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b4 in still_not-bound_in b2 & not b5 in still_not-bound_in b3 holds
|- (Ex b4,b1) => (Ex b5,b2)
proof end;

theorem Th33: :: CQC_THE2:33
canceled;

theorem Th34: :: CQC_THE2:34
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 => b2)) => ((All b3,b1) => (All b3,b2))
proof end;

theorem Th35: :: CQC_THE2:35
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st |- All b3,(b1 => b2) holds
|- (All b3,b1) => (All b3,b2)
proof end;

theorem Th36: :: CQC_THE2:36
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 <=> b2)) => ((All b3,b1) <=> (All b3,b2))
proof end;

theorem Th37: :: CQC_THE2:37
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st |- All b3,(b1 <=> b2) holds
|- (All b3,b1) <=> (All b3,b2)
proof end;

theorem Th38: :: CQC_THE2:38
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 => b2)) => ((Ex b3,b1) => (Ex b3,b2))
proof end;

theorem Th39: :: CQC_THE2:39
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st |- All b3,(b1 => b2) holds
|- (Ex b3,b1) => (Ex b3,b2)
proof end;

theorem Th40: :: CQC_THE2:40
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- (All b3,(b1 '&' b2)) => ((All b3,b1) '&' (All b3,b2)) & |- ((All b3,b1) '&' (All b3,b2)) => (All b3,(b1 '&' b2)) )
proof end;

theorem Th41: :: CQC_THE2:41
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 '&' b2)) <=> ((All b3,b1) '&' (All b3,b2))
proof end;

theorem Th42: :: CQC_THE2:42
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- All b3,(b1 '&' b2) iff |- (All b3,b1) '&' (All b3,b2) )
proof end;

theorem Th43: :: CQC_THE2:43
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- ((All b3,b1) 'or' (All b3,b2)) => (All b3,(b1 'or' b2))
proof end;

theorem Th44: :: CQC_THE2:44
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- (Ex b3,(b1 'or' b2)) => ((Ex b3,b1) 'or' (Ex b3,b2)) & |- ((Ex b3,b1) 'or' (Ex b3,b2)) => (Ex b3,(b1 'or' b2)) )
proof end;

theorem Th45: :: CQC_THE2:45
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (Ex b3,(b1 'or' b2)) <=> ((Ex b3,b1) 'or' (Ex b3,b2))
proof end;

theorem Th46: :: CQC_THE2:46
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- Ex b3,(b1 'or' b2) iff |- (Ex b3,b1) 'or' (Ex b3,b2) )
proof end;

theorem Th47: :: CQC_THE2:47
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (Ex b3,(b1 '&' b2)) => ((Ex b3,b1) '&' (Ex b3,b2))
proof end;

theorem Th48: :: CQC_THE2:48
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st |- Ex b3,(b1 '&' b2) holds
|- (Ex b3,b1) '&' (Ex b3,b2)
proof end;

theorem Th49: :: CQC_THE2:49
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds
( |- (All b2,('not' ('not' b1))) => (All b2,b1) & |- (All b2,b1) => (All b2,('not' ('not' b1))) )
proof end;

theorem Th50: :: CQC_THE2:50
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- (All b2,('not' ('not' b1))) <=> (All b2,b1)
proof end;

theorem Th51: :: CQC_THE2:51
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds
( |- (Ex b2,('not' ('not' b1))) => (Ex b2,b1) & |- (Ex b2,b1) => (Ex b2,('not' ('not' b1))) )
proof end;

theorem Th52: :: CQC_THE2:52
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- (Ex b2,('not' ('not' b1))) <=> (Ex b2,b1)
proof end;

theorem Th53: :: CQC_THE2:53
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds
( |- ('not' (Ex b2,('not' b1))) => (All b2,b1) & |- (All b2,b1) => ('not' (Ex b2,('not' b1))) )
proof end;

theorem Th54: :: CQC_THE2:54
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- ('not' (Ex b2,('not' b1))) <=> (All b2,b1)
proof end;

theorem Th55: :: CQC_THE2:55
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds
( |- ('not' (All b2,b1)) => (Ex b2,('not' b1)) & |- (Ex b2,('not' b1)) => ('not' (All b2,b1)) )
proof end;

theorem Th56: :: CQC_THE2:56
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- ('not' (All b2,b1)) <=> (Ex b2,('not' b1))
proof end;

theorem Th57: :: CQC_THE2:57
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds
( |- ('not' (Ex b2,b1)) => (All b2,('not' b1)) & |- (All b2,('not' b1)) => ('not' (Ex b2,b1)) )
proof end;

theorem Th58: :: CQC_THE2:58
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- (All b2,('not' b1)) <=> ('not' (Ex b2,b1))
proof end;

theorem Th59: :: CQC_THE2:59
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable holds
( |- (All b2,(All b3,b1)) => (All b3,(All b2,b1)) & |- (All b2,b3,b1) => (All b3,b2,b1) )
proof end;

theorem Th60: :: CQC_THE2:60
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b5 in still_not-bound_in b3 holds
|- (All b4,(All b5,b2)) => (All b4,b1)
proof end;

theorem Th61: :: CQC_THE2:61
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable holds
( |- (Ex b2,(Ex b3,b1)) => (Ex b3,(Ex b2,b1)) & |- (Ex b2,b3,b1) => (Ex b3,b2,b1) )
proof end;

theorem Th62: :: CQC_THE2:62
for b1, b2 being Element of CQC-WFF
for b3 being QC-formula
for b4, b5 being bound_QC-variable st b1 = b3 . b4 & b2 = b3 . b5 & not b5 in still_not-bound_in b3 holds
|- (Ex b4,b1) => (Ex b4,b5,b2)
proof end;

theorem Th63: :: CQC_THE2:63
for b1 being Element of CQC-WFF
for b2, b3 being bound_QC-variable holds |- (Ex b2,(All b3,b1)) => (All b3,(Ex b2,b1))
proof end;

theorem Th64: :: CQC_THE2:64
for b1 being Element of CQC-WFF
for b2 being bound_QC-variable holds |- Ex b2,(b1 <=> b1)
proof end;

theorem Th65: :: CQC_THE2:65
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- (Ex b3,(b1 => b2)) => ((All b3,b1) => (Ex b3,b2)) & |- ((All b3,b1) => (Ex b3,b2)) => (Ex b3,(b1 => b2)) )
proof end;

theorem Th66: :: CQC_THE2:66
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (Ex b3,(b1 => b2)) <=> ((All b3,b1) => (Ex b3,b2))
proof end;

theorem Th67: :: CQC_THE2:67
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds
( |- Ex b3,(b1 => b2) iff |- (All b3,b1) => (Ex b3,b2) )
proof end;

theorem Th68: :: CQC_THE2:68
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 '&' b2)) => (b1 '&' (All b3,b2))
proof end;

theorem Th69: :: CQC_THE2:69
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (All b3,(b1 '&' b2)) => ((All b3,b1) '&' b2)
proof end;

theorem Th70: :: CQC_THE2:70
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (b1 '&' (All b3,b2)) => (All b3,(b1 '&' b2))
proof end;

theorem Th71: :: CQC_THE2:71
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 & |- b1 '&' (All b3,b2) holds
|- All b3,(b1 '&' b2)
proof end;

theorem Th72: :: CQC_THE2:72
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- (b1 'or' (All b3,b2)) => (All b3,(b1 'or' b2)) & |- (All b3,(b1 'or' b2)) => (b1 'or' (All b3,b2)) )
proof end;

theorem Th73: :: CQC_THE2:73
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (b1 'or' (All b3,b2)) <=> (All b3,(b1 'or' b2))
proof end;

theorem Th74: :: CQC_THE2:74
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- b1 'or' (All b3,b2) iff |- All b3,(b1 'or' b2) )
proof end;

theorem Th75: :: CQC_THE2:75
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- (b1 '&' (Ex b3,b2)) => (Ex b3,(b1 '&' b2)) & |- (Ex b3,(b1 '&' b2)) => (b1 '&' (Ex b3,b2)) )
proof end;

theorem Th76: :: CQC_THE2:76
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (b1 '&' (Ex b3,b2)) <=> (Ex b3,(b1 '&' b2))
proof end;

theorem Th77: :: CQC_THE2:77
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- b1 '&' (Ex b3,b2) iff |- Ex b3,(b1 '&' b2) )
proof end;

Lemma60: for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (All b3,(b1 => b2)) => (b1 => (All b3,b2))
proof end;

theorem Th78: :: CQC_THE2:78
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- (All b3,(b1 => b2)) => (b1 => (All b3,b2)) & |- (b1 => (All b3,b2)) => (All b3,(b1 => b2)) )
proof end;

theorem Th79: :: CQC_THE2:79
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (b1 => (All b3,b2)) <=> (All b3,(b1 => b2))
proof end;

theorem Th80: :: CQC_THE2:80
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- All b3,(b1 => b2) iff |- b1 => (All b3,b2) )
proof end;

theorem Th81: :: CQC_THE2:81
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (Ex b3,(b2 => b1)) => ((All b3,b2) => b1)
proof end;

theorem Th82: :: CQC_THE2:82
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- ((All b3,b1) => b2) => (Ex b3,(b1 => b2))
proof end;

theorem Th83: :: CQC_THE2:83
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- (All b3,b2) => b1 iff |- Ex b3,(b2 => b1) )
proof end;

theorem Th84: :: CQC_THE2:84
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- ((Ex b3,b2) => b1) => (All b3,(b2 => b1)) & |- (All b3,(b2 => b1)) => ((Ex b3,b2) => b1) )
proof end;

theorem Th85: :: CQC_THE2:85
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- ((Ex b3,b2) => b1) <=> (All b3,(b2 => b1))
proof end;

theorem Th86: :: CQC_THE2:86
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- (Ex b3,b2) => b1 iff |- All b3,(b2 => b1) )
proof end;

theorem Th87: :: CQC_THE2:87
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (Ex b3,(b1 => b2)) => (b1 => (Ex b3,b2))
proof end;

theorem Th88: :: CQC_THE2:88
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable holds |- (b1 => (Ex b3,b2)) => (Ex b3,(b1 => b2))
proof end;

theorem Th89: :: CQC_THE2:89
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
|- (b1 => (Ex b3,b2)) <=> (Ex b3,(b1 => b2))
proof end;

theorem Th90: :: CQC_THE2:90
for b1, b2 being Element of CQC-WFF
for b3 being bound_QC-variable st not b3 in still_not-bound_in b1 holds
( |- b1 => (Ex b3,b2) iff |- Ex b3,(b1 => b2) )
proof end;

theorem Th91: :: CQC_THE2:91
for b1 being Element of CQC-WFF holds {b1} |- b1
proof end;

theorem Th92: :: CQC_THE2:92
for b1, b2 being Element of CQC-WFF holds Cn ({b1} \/ {b2}) = Cn {(b1 '&' b2)}
proof end;

theorem Th93: :: CQC_THE2:93
for b1, b2, b3 being Element of CQC-WFF holds
( {b1,b2} |- b3 iff {(b1 '&' b2)} |- b3 )
proof end;

theorem Th94: :: CQC_THE2:94
for b1 being Subset of CQC-WFF
for b2 being Element of CQC-WFF
for b3 being bound_QC-variable st b1 |- b2 holds
b1 |- All b3,b2
proof end;

theorem Th95: :: CQC_THE2:95
for b1 being Subset of CQC-WFF
for b2, b3 being Element of CQC-WFF
for b4 being bound_QC-variable st not b4 in still_not-bound_in b2 holds
b1 |- (All b4,(b2 => b3)) => (b2 => (All b4,b3))
proof end;

theorem Th96: :: CQC_THE2:96
for b1 being Subset of CQC-WFF
for b2, b3 being Element of CQC-WFF st b2 is closed & b1 \/ {b2} |- b3 holds
b1 |- b2 => b3
proof end;