let a be non empty at_most_one FinSequence of REAL ; for opt1, opt2 being Element of NAT st ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt1 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt1 <= card (rng f) ) ) & ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt2 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt2 <= card (rng f) ) ) holds
opt1 = opt2
let opt1, opt2 be Element of NAT ; ( ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt1 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt1 <= card (rng f) ) ) & ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt2 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt2 <= card (rng f) ) ) implies opt1 = opt2 )
assume that
L000:
ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt1 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt1 <= card (rng f) ) )
and
L001:
ex g being non empty FinSequence of NAT st
( dom g = dom a & ( for j being Nat st j in rng g holds
SumBin (a,g,{j}) <= 1 ) & opt2 = card (rng g) & ( for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt2 <= card (rng f) ) )
; opt1 = opt2
consider g1 being non empty FinSequence of NAT such that
L010:
dom g1 = dom a
and
L011:
for j being Nat st j in rng g1 holds
SumBin (a,g1,{j}) <= 1
and
L012:
opt1 = card (rng g1)
and
L013:
for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt1 <= card (rng f)
by L000;
consider g2 being non empty FinSequence of NAT such that
L020:
dom g2 = dom a
and
L021:
for j being Nat st j in rng g2 holds
SumBin (a,g2,{j}) <= 1
and
L022:
opt2 = card (rng g2)
and
L023:
for f being non empty FinSequence of NAT st dom f = dom a & ( for j being Nat st j in rng f holds
SumBin (a,f,{j}) <= 1 ) holds
opt2 <= card (rng f)
by L001;
L050:
opt1 <= opt2
by L020, L021, L013, L022;
opt2 <= opt1
by L010, L011, L023, L012;
hence
opt1 = opt2
by L050, XXREAL_0:1; verum