We laten nu nog even zien dat het n-de orde pseudoquotiënt inderdaad aan onze verwachtingen voldoet. In onze eerdere verkenningen zijn we nagegaan hoe een oplossing eruit zou moeten zien
als deze bestaat, maar we hebben strikt genomen niet aangetoond
dat deze bestaat.
Voor c
d en het positieve natuurlijke getal n
gw(a~b,c~d) geldt:
(c~d) . ((a~b) //
n (c~d)) = (a~b) .
1n .
Bewijs:
Laat c
d en het positieve natuurlijke getal n
gw(a~b,c~d).
Voor het gemak van de bewijsvoering schrijven we:
\( (e,f) \, = \, (c \sim d) \, . \, ((a \sim b) \,\, //_n \,\, (c \sim d)) \)
,
\( (g,h) \, = \, (a \sim b) \, . \, \underline{1}^n \)
.
Voor (e,f) vinden we:
\( e - f \, = \, rw((e,f)) \)
\( e - f \, = \, rw((c \sim d) \, . \, ((a \sim b) \,\, //_n \,\, (c \sim d))) \)
\( e \, - f \, = \,\, rw \left ( (c \sim d) \,\, . \,\, \left ( \left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right \} \right ) \sim \left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right \} \right ) \right ) \right ) \)
\( e \, - f \, = \, rw( c \sim d) \,\, . \,\, rw \left (\left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right \} \right ) \, \sim \, \left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right \} \right ) \right ) \)
\( e - f \, = \, (c - d) \,\, . \,\, \left ( \frac{1}{2} \, . \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right ) \,\, - \,\, \frac{1}{2} \, . \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right ) \right ) \)
\( e - f \, = \, (c - d) \,\, . \,\, \frac{1}{2} \, . \left ( \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right ) \, - \, \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right ) \right ) \)
\( e - f \, = \, (c - d) \,\, . \,\, \frac{1}{2} \, . \left ( \frac{a - b}{c - d} \, + \, \frac{a - b}{c - d} \right ) \)
\( e - f \, = \, (c - d) \,\, . \,\, \frac{a - b}{c - d} \)
\( e - f \, = \, a - b \)
.
\( e + f \, = \, aw((e,f)) \)
\( e + f \, = \, aw((c \sim d) \, . \, ((a \sim b) \,\, //_n \,\, (c \sim d))) \)
\( e \, + \, f \, = \,\, aw \left ( (c \sim d) \,\, . \,\, \left (\left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right \} \right ) \sim \left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right \} \right ) \right ) \right ) \)
\( e \, + \, f \, = \, aw(c \sim d) \,\, . \,\, aw \left (\left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right \} \right ) \, \sim \, \left ( \frac{1}{2} \, . \left \{ \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right \} \right ) \right ) \)
\( e + f \, = \, (c + d) \,\, . \,\, \left ( \frac{1}{2} \, . \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right ) \,\, + \,\, \frac{1}{2} \, . \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right ) \right ) \)
\( e + f \, = \, (c + d) \,\, . \,\, \frac{1}{2} \, . \left ( \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a - b}{c - d} \right ) \, + \, \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, - \, \frac{a - b}{c - d} \right ) \right ) \)
\( e + f \, = \, (c + d) \,\, . \,\, \frac{1}{2} \, . \left ( \frac{a + b}{c + d} \,\, . \,\, 3^n \, + \, \frac{a + b}{c + d} \,\, . \,\, 3^n \right ) \)
\( e + f \, = \, (c + d) \,\, . \,\, \frac{a + b}{c + d} \,\, . \,\, 3^n \)
\( e + f \, = \, (a + b) \,\, . \,\, 3^n \)
.
\( 2 . e \, = \, (a + b) \,\, . \,\, 3^n \, + \, (a - b) \)
\( e \, = \, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, + \, (a - b) ) \)
.
\( 2 . f \, = \, (a + b) \,\, . \,\, 3^n \, - \, (a - b) \)
\( f \, = \, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, - \, (a - b) ) \)
.
\( (e,f) \, = \, \left ( \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, + \, (a - b) ) \,\, , \,\, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, - \, (a - b) ) \right ) \)
.
Voor (g,h) vinden we:
\( g - h \, = \, rw((g,h)) \)
\( g - h \, = \, rw((a \sim b) \, . \, \underline{1}^n ) \)
\( g - h \, = \, rw(a \sim b)\, . \, rw(\underline{1}^n ) \)
\( g - h \, = \, (a - b)\, . \, (rw(\underline{1}))^n \)
\( g - h \, = \, (a - b)\, . \, 1^n \)
\( g - h \, = \, (a - b)\, . \, 1 \)
\( g - h \, = \, (a - b) \)
.
\( g + h \, = \, aw((g,h)) \)
\( g + h \, = \, aw((a \sim b) \, . \, \underline{1}^n ) \)
\( g + h \, = \, aw((a \sim b) \, . \, (2.1 \, , \, 1)^n ) \)
\( g + h \, = \, aw((a \sim b) \, . \, (2,1)^n ) \)
\( g + h \, \, = \, aw(a \sim b)\, . \, aw((2,1)^n ) \)
\( g + h \, = \, (a + b)\, . \, (aw((2,1)))^n \)
\( g + h \, = \, (a + b)\, . \, 3^n \)
.
\( 2.g \, = \, (a + b)\, . \, 3^n \, + \, (a - b) \)
\( g \, = \, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, + \, (a - b) ) \)
.
\( 2 .h \, = \, (a + b) \,\, . \,\, 3^n \, - \, (a - b) \)
\( h \, = \, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, - \, (a - b) ) \)
.
\( (g,h) \, = \, \left ( \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, + \, (a - b) ) \,\, , \,\, \frac{1}{2} \, . \, ( (a + b) \,\, . \,\, 3^n \, - \, (a - b) ) \right ) \)
.
Samenvattend:
\( (e,f) = (g,h) \)
\( (c \sim d) \, . \, ((a \sim b) \,\, //_n \,\, (c \sim d)) \, = \, (a \sim b) \, . \, \underline{1}^n \)
.
Dus geldt voor c
d en positieve natuurlijke getallen n
gw(a~b,c~d) inderdaad dat:
(c~d) . ((a~b) //
n (c~d)) = (a~b) .
1n .