Lm1:
for Y being non empty set
for a, b being Function of Y,BOOLEAN holds a '&' b '<' a
Lm2:
for Y being non empty set
for a, b, c being Function of Y,BOOLEAN holds
( (a '&' b) '&' c '<' a & (a '&' b) '&' c '<' b )
Lm3:
for Y being non empty set
for a, b, c, d being Function of Y,BOOLEAN holds
( ((a '&' b) '&' c) '&' d '<' a & ((a '&' b) '&' c) '&' d '<' b )
Lm4:
for Y being non empty set
for a, b, c, d, e being Function of Y,BOOLEAN holds
( (((a '&' b) '&' c) '&' d) '&' e '<' a & (((a '&' b) '&' c) '&' d) '&' e '<' b )
Lm5:
for Y being non empty set
for a, b, c, d, e, f being Function of Y,BOOLEAN holds
( ((((a '&' b) '&' c) '&' d) '&' e) '&' f '<' a & ((((a '&' b) '&' c) '&' d) '&' e) '&' f '<' b )
Lm6:
for Y being non empty set
for a, b, c, d, e, f, g being Function of Y,BOOLEAN holds
( (((((a '&' b) '&' c) '&' d) '&' e) '&' f) '&' g '<' a & (((((a '&' b) '&' c) '&' d) '&' e) '&' f) '&' g '<' b )
Lm7:
for Y being non empty set
for a1, b1, c1, a2, b2, c2 being Function of Y,BOOLEAN holds (((((((a1 'imp' a2) '&' (b1 'imp' b2)) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (a2 '&' b2))) '&' ('not' (a2 '&' c2))) '&' ('not' (b2 '&' c2))) 'imp' (((((a1 'imp' a2) '&' (b1 'imp' b2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (c2 '&' a2))) '&' ('not' (c2 '&' b2))) = I_el Y
Lm8:
for Y being non empty set
for a1, b1, c1, a2, b2, c2 being Function of Y,BOOLEAN holds (((((((a1 'imp' a2) '&' (b1 'imp' b2)) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (a2 '&' b2))) '&' ('not' (a2 '&' c2))) '&' ('not' (b2 '&' c2))) 'imp' (((((a1 'imp' a2) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (b2 '&' a2))) '&' ('not' (b2 '&' c2))) = I_el Y
Lm9:
for Y being non empty set
for a1, b1, c1, a2, b2, c2 being Function of Y,BOOLEAN holds (((((((a1 'imp' a2) '&' (b1 'imp' b2)) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (a2 '&' b2))) '&' ('not' (a2 '&' c2))) '&' ('not' (b2 '&' c2))) 'imp' (((((b1 'imp' b2) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1)) '&' ('not' (a2 '&' b2))) '&' ('not' (a2 '&' c2))) = I_el Y
Lm1:
for Y being non empty set
for a, b, c being Function of Y,BOOLEAN holds ((a '&' ('not' b)) 'or' (b '&' ('not' c))) 'or' (c '&' ('not' a)) '<' ((b '&' ('not' a)) 'or' (c '&' ('not' b))) 'or' (a '&' ('not' c))
Lm2:
for Y being non empty set
for a, b, c being Function of Y,BOOLEAN holds ((a 'or' ('not' b)) '&' (b 'or' ('not' c))) '&' (c 'or' ('not' a)) '<' ((b 'or' ('not' a)) '&' (c 'or' ('not' b))) '&' (a 'or' ('not' c))
Lm3:
for Y being non empty set
for a1, a2, b1, b2 being Function of Y,BOOLEAN holds (((a1 'imp' b1) '&' (a2 'imp' b2)) '&' (a1 'or' a2)) '&' ('not' (b1 '&' b2)) '<' (((b1 'imp' a1) '&' (b2 'imp' a2)) '&' (b1 'or' b2)) '&' ('not' (a1 '&' a2))
Lm4:
for Y being non empty set
for a, b, c being Function of Y,BOOLEAN holds (((('not' a) '&' b) '&' c) 'or' ((a '&' ('not' b)) '&' c)) 'or' ((a '&' b) '&' ('not' c)) '<' (a 'or' b) '&' ('not' ((a '&' b) '&' c))