Proof explaining opposite of what is observed Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)I need to solve one equation, but I dont know how to solve equation with floor functionsWhat is the origin of the (nearly obsolete) term “binary decimal”?What are the last four digits in the binary expansion $1234^5555 + 4321^5555$?Name for numbers with a single non-zero digit.Prove that the number of bits in a positive $m$-bit integer $n$ is $n-sum_k=1^m-1 lfloor n/2^k rfloor$Find number of digits of N in base bTrying to understand $2$'s complementConfusion about normalised floating point number systemsClosed Form Addition of BCD numbersPerform addition that disregards carriesThe digit at position $n$ of the number $x$ in base $m$
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Proof explaining opposite of what is observed
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)I need to solve one equation, but I dont know how to solve equation with floor functionsWhat is the origin of the (nearly obsolete) term “binary decimal”?What are the last four digits in the binary expansion $1234^5555 + 4321^5555$?Name for numbers with a single non-zero digit.Prove that the number of bits in a positive $m$-bit integer $n$ is $n-sum_k=1^m-1 lfloor n/2^k rfloor$Find number of digits of N in base bTrying to understand $2$'s complementConfusion about normalised floating point number systemsClosed Form Addition of BCD numbersPerform addition that disregards carriesThe digit at position $n$ of the number $x$ in base $m$
$begingroup$
Little time ago I started to playing with binary numbers and just have a little fun . I found some pretty interesting things. I want to ask if my own findings have some official names or no .Also I would like to get help with finding proofs. All of my finding are related to numbers with fixed maximum value, just like in the computer.
So the first interesting thing I found is 'bitwise negation' operation for non binary numbers.
we already know definition of bitwise negation operator for binary numbers, every 1 became 0 and every 0 became 1 .
It is also can be written by this form :
$x' = 2^r -1 -x $
$ r=textnumber of bites $
$ x=textvariable$
$ x'=textbitwise negated value of variable in binary form$
This is true , because the sum of the number and it's negative is always equal to $2^r-1$ .
I trought ,we could make this operations happen in another number systems simply by replacing base .
So the following equation would work :
$x' = b^r-1 -x$
where
$b=text base$
So for example , the 'bitwise negation' of decimal number 1250 with 4 digits would be
9999-1250 = 8749
I also 'invented' my own addition pattern, which I will be explaining right now.
The new addition system Im calling 'reflow' instread of overflow, because every bit which is overflowing , will be moved to the right side.
Imagine having two numbers with 4 bits each .
Both of them have value of 1000
When you add then in normal addition, it will overflow , and the result will be 0000
1000
+1000
1|0000 | this sign means, it is overflowed
but in my operation it would reflow, which means following.
1000
+1000
1|0000 = 0001
└────╝
I also writed it in form of equation :
$a➕c = a+c- lfloor fraca+cb^rrfloor(b^r-1)$
a,c = variables
b = base (decimal = 10 , binary =2 etc)
r = number of digits, bits
I was studying this a little bit and I surprisingly found, that in every case , in interval $[0,b^r-2]$ there is true that :
$n➕m= (n'➕m')'$
we suppose that :
$G=b^r$
$g=b^r-1$
So expanded it is:
$n+m-glfloorfracn+mGrfloor = g-(g-n+g-m-glfloorfracg-n+g-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=g-(2g-n-m-glfloorfrac2g-n-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=-g+n+m+glfloorfrac2g-n-mGrfloor $
$-glfloorfracn+mGrfloor=g(lfloorfrac2g-n-mGrfloor-1)$
$-lfloorfracn+mGrfloor = lfloorfrac2g-n-mGrfloor-1$
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1$
What next guys? I already tried to ask here to solve just this equation, this is the response LINK but the result is completely oposite to what i was looking for. The result is exactly when it shouldnt be true.. Did I made some problem while solving it?
Here is also link to Desmos graphing tool with some of the formulas LINK
Thank you for your responses
Patrik Bašo
functions modular-arithmetic arithmetic number-systems additive-categories
$endgroup$
add a comment |
$begingroup$
Little time ago I started to playing with binary numbers and just have a little fun . I found some pretty interesting things. I want to ask if my own findings have some official names or no .Also I would like to get help with finding proofs. All of my finding are related to numbers with fixed maximum value, just like in the computer.
So the first interesting thing I found is 'bitwise negation' operation for non binary numbers.
we already know definition of bitwise negation operator for binary numbers, every 1 became 0 and every 0 became 1 .
It is also can be written by this form :
$x' = 2^r -1 -x $
$ r=textnumber of bites $
$ x=textvariable$
$ x'=textbitwise negated value of variable in binary form$
This is true , because the sum of the number and it's negative is always equal to $2^r-1$ .
I trought ,we could make this operations happen in another number systems simply by replacing base .
So the following equation would work :
$x' = b^r-1 -x$
where
$b=text base$
So for example , the 'bitwise negation' of decimal number 1250 with 4 digits would be
9999-1250 = 8749
I also 'invented' my own addition pattern, which I will be explaining right now.
The new addition system Im calling 'reflow' instread of overflow, because every bit which is overflowing , will be moved to the right side.
Imagine having two numbers with 4 bits each .
Both of them have value of 1000
When you add then in normal addition, it will overflow , and the result will be 0000
1000
+1000
1|0000 | this sign means, it is overflowed
but in my operation it would reflow, which means following.
1000
+1000
1|0000 = 0001
└────╝
I also writed it in form of equation :
$a➕c = a+c- lfloor fraca+cb^rrfloor(b^r-1)$
a,c = variables
b = base (decimal = 10 , binary =2 etc)
r = number of digits, bits
I was studying this a little bit and I surprisingly found, that in every case , in interval $[0,b^r-2]$ there is true that :
$n➕m= (n'➕m')'$
we suppose that :
$G=b^r$
$g=b^r-1$
So expanded it is:
$n+m-glfloorfracn+mGrfloor = g-(g-n+g-m-glfloorfracg-n+g-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=g-(2g-n-m-glfloorfrac2g-n-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=-g+n+m+glfloorfrac2g-n-mGrfloor $
$-glfloorfracn+mGrfloor=g(lfloorfrac2g-n-mGrfloor-1)$
$-lfloorfracn+mGrfloor = lfloorfrac2g-n-mGrfloor-1$
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1$
What next guys? I already tried to ask here to solve just this equation, this is the response LINK but the result is completely oposite to what i was looking for. The result is exactly when it shouldnt be true.. Did I made some problem while solving it?
Here is also link to Desmos graphing tool with some of the formulas LINK
Thank you for your responses
Patrik Bašo
functions modular-arithmetic arithmetic number-systems additive-categories
$endgroup$
1
$begingroup$
Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24
add a comment |
$begingroup$
Little time ago I started to playing with binary numbers and just have a little fun . I found some pretty interesting things. I want to ask if my own findings have some official names or no .Also I would like to get help with finding proofs. All of my finding are related to numbers with fixed maximum value, just like in the computer.
So the first interesting thing I found is 'bitwise negation' operation for non binary numbers.
we already know definition of bitwise negation operator for binary numbers, every 1 became 0 and every 0 became 1 .
It is also can be written by this form :
$x' = 2^r -1 -x $
$ r=textnumber of bites $
$ x=textvariable$
$ x'=textbitwise negated value of variable in binary form$
This is true , because the sum of the number and it's negative is always equal to $2^r-1$ .
I trought ,we could make this operations happen in another number systems simply by replacing base .
So the following equation would work :
$x' = b^r-1 -x$
where
$b=text base$
So for example , the 'bitwise negation' of decimal number 1250 with 4 digits would be
9999-1250 = 8749
I also 'invented' my own addition pattern, which I will be explaining right now.
The new addition system Im calling 'reflow' instread of overflow, because every bit which is overflowing , will be moved to the right side.
Imagine having two numbers with 4 bits each .
Both of them have value of 1000
When you add then in normal addition, it will overflow , and the result will be 0000
1000
+1000
1|0000 | this sign means, it is overflowed
but in my operation it would reflow, which means following.
1000
+1000
1|0000 = 0001
└────╝
I also writed it in form of equation :
$a➕c = a+c- lfloor fraca+cb^rrfloor(b^r-1)$
a,c = variables
b = base (decimal = 10 , binary =2 etc)
r = number of digits, bits
I was studying this a little bit and I surprisingly found, that in every case , in interval $[0,b^r-2]$ there is true that :
$n➕m= (n'➕m')'$
we suppose that :
$G=b^r$
$g=b^r-1$
So expanded it is:
$n+m-glfloorfracn+mGrfloor = g-(g-n+g-m-glfloorfracg-n+g-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=g-(2g-n-m-glfloorfrac2g-n-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=-g+n+m+glfloorfrac2g-n-mGrfloor $
$-glfloorfracn+mGrfloor=g(lfloorfrac2g-n-mGrfloor-1)$
$-lfloorfracn+mGrfloor = lfloorfrac2g-n-mGrfloor-1$
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1$
What next guys? I already tried to ask here to solve just this equation, this is the response LINK but the result is completely oposite to what i was looking for. The result is exactly when it shouldnt be true.. Did I made some problem while solving it?
Here is also link to Desmos graphing tool with some of the formulas LINK
Thank you for your responses
Patrik Bašo
functions modular-arithmetic arithmetic number-systems additive-categories
$endgroup$
Little time ago I started to playing with binary numbers and just have a little fun . I found some pretty interesting things. I want to ask if my own findings have some official names or no .Also I would like to get help with finding proofs. All of my finding are related to numbers with fixed maximum value, just like in the computer.
So the first interesting thing I found is 'bitwise negation' operation for non binary numbers.
we already know definition of bitwise negation operator for binary numbers, every 1 became 0 and every 0 became 1 .
It is also can be written by this form :
$x' = 2^r -1 -x $
$ r=textnumber of bites $
$ x=textvariable$
$ x'=textbitwise negated value of variable in binary form$
This is true , because the sum of the number and it's negative is always equal to $2^r-1$ .
I trought ,we could make this operations happen in another number systems simply by replacing base .
So the following equation would work :
$x' = b^r-1 -x$
where
$b=text base$
So for example , the 'bitwise negation' of decimal number 1250 with 4 digits would be
9999-1250 = 8749
I also 'invented' my own addition pattern, which I will be explaining right now.
The new addition system Im calling 'reflow' instread of overflow, because every bit which is overflowing , will be moved to the right side.
Imagine having two numbers with 4 bits each .
Both of them have value of 1000
When you add then in normal addition, it will overflow , and the result will be 0000
1000
+1000
1|0000 | this sign means, it is overflowed
but in my operation it would reflow, which means following.
1000
+1000
1|0000 = 0001
└────╝
I also writed it in form of equation :
$a➕c = a+c- lfloor fraca+cb^rrfloor(b^r-1)$
a,c = variables
b = base (decimal = 10 , binary =2 etc)
r = number of digits, bits
I was studying this a little bit and I surprisingly found, that in every case , in interval $[0,b^r-2]$ there is true that :
$n➕m= (n'➕m')'$
we suppose that :
$G=b^r$
$g=b^r-1$
So expanded it is:
$n+m-glfloorfracn+mGrfloor = g-(g-n+g-m-glfloorfracg-n+g-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=g-(2g-n-m-glfloorfrac2g-n-mGrfloor)$
$n+m-glfloorfracn+mGrfloor=-g+n+m+glfloorfrac2g-n-mGrfloor $
$-glfloorfracn+mGrfloor=g(lfloorfrac2g-n-mGrfloor-1)$
$-lfloorfracn+mGrfloor = lfloorfrac2g-n-mGrfloor-1$
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1$
What next guys? I already tried to ask here to solve just this equation, this is the response LINK but the result is completely oposite to what i was looking for. The result is exactly when it shouldnt be true.. Did I made some problem while solving it?
Here is also link to Desmos graphing tool with some of the formulas LINK
Thank you for your responses
Patrik Bašo
functions modular-arithmetic arithmetic number-systems additive-categories
functions modular-arithmetic arithmetic number-systems additive-categories
edited Apr 1 at 7:41
Patrik Bašo
asked Mar 31 at 19:21
Patrik BašoPatrik Bašo
206
206
1
$begingroup$
Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24
add a comment |
1
$begingroup$
Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24
1
1
$begingroup$
Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24
$begingroup$
Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
You've done pretty well in your proof, which requires just one extra step.
If $ m+n le g-1 $, then $$ 2G>2gge 2g-n-m ge g+1= G .$$
Thus, since $ 2G>2g-n-mge G $ in this case, you have $ lfloorfrac2g-n-mGrfloor=1 $, $ lfloorfracn+mGrfloor=0 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
On the other hand, if $ m+n>g-1 $, then (because $ m,n < g $):
$$0<2g-n-m<g+1=G ,$$
and so $ lfloorfrac2g-n-mGrfloor=0 $, $ lfloorfracn+mGrfloor=1 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
One thing you should be made aware of, however, is that when writing out proofs, you should avoid just writing down the equation you're trying to prove and manipulating it into something which is purportedly equivalent. The main reason why this is inadvisable is the that the flow of logic is wrong:
$$
left[matrixmboxProposition\ mboxto be provedright]implies P_2implies P_3implies dots impliesleft[matrixmboxTrue\ mboxPropositionright] ,$$
and the final proposition will be equivalent to the original only if every step in your manipulation is reversible. If that does happen to be true, then you will be able to reverse the implications in the above chain of propositions to obtain a valid proof:
$$
left[matrixmboxTrue\ mboxpropostionright]implies dots implies P_3implies P_2 impliesleft[matrixmboxProposition\ mboxto be provedright] ,$$
and this is the form which any proof you give should take.
As it turns out, your addition, $ "➕" $, is essentially the same thing as addition modulo $ b^r-1 $:
$$ a➕c equiv a+c pmodb^r-1 .$$
Your negation is also the same as negation modulo $ b^r-1 $:
$$ m'equiv -m pmodb^r-1 .$$
So your observation that $ n➕m= (n'➕m')' $ is equivalent to the equation:
$$ m+nequiv -left(left(-mright)+left(-nright)right) pmodb^r-1 ,$$
which is not difficult to prove using modular arithmetic.
$endgroup$
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
add a comment |
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votes
$begingroup$
You've done pretty well in your proof, which requires just one extra step.
If $ m+n le g-1 $, then $$ 2G>2gge 2g-n-m ge g+1= G .$$
Thus, since $ 2G>2g-n-mge G $ in this case, you have $ lfloorfrac2g-n-mGrfloor=1 $, $ lfloorfracn+mGrfloor=0 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
On the other hand, if $ m+n>g-1 $, then (because $ m,n < g $):
$$0<2g-n-m<g+1=G ,$$
and so $ lfloorfrac2g-n-mGrfloor=0 $, $ lfloorfracn+mGrfloor=1 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
One thing you should be made aware of, however, is that when writing out proofs, you should avoid just writing down the equation you're trying to prove and manipulating it into something which is purportedly equivalent. The main reason why this is inadvisable is the that the flow of logic is wrong:
$$
left[matrixmboxProposition\ mboxto be provedright]implies P_2implies P_3implies dots impliesleft[matrixmboxTrue\ mboxPropositionright] ,$$
and the final proposition will be equivalent to the original only if every step in your manipulation is reversible. If that does happen to be true, then you will be able to reverse the implications in the above chain of propositions to obtain a valid proof:
$$
left[matrixmboxTrue\ mboxpropostionright]implies dots implies P_3implies P_2 impliesleft[matrixmboxProposition\ mboxto be provedright] ,$$
and this is the form which any proof you give should take.
As it turns out, your addition, $ "➕" $, is essentially the same thing as addition modulo $ b^r-1 $:
$$ a➕c equiv a+c pmodb^r-1 .$$
Your negation is also the same as negation modulo $ b^r-1 $:
$$ m'equiv -m pmodb^r-1 .$$
So your observation that $ n➕m= (n'➕m')' $ is equivalent to the equation:
$$ m+nequiv -left(left(-mright)+left(-nright)right) pmodb^r-1 ,$$
which is not difficult to prove using modular arithmetic.
$endgroup$
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
add a comment |
$begingroup$
You've done pretty well in your proof, which requires just one extra step.
If $ m+n le g-1 $, then $$ 2G>2gge 2g-n-m ge g+1= G .$$
Thus, since $ 2G>2g-n-mge G $ in this case, you have $ lfloorfrac2g-n-mGrfloor=1 $, $ lfloorfracn+mGrfloor=0 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
On the other hand, if $ m+n>g-1 $, then (because $ m,n < g $):
$$0<2g-n-m<g+1=G ,$$
and so $ lfloorfrac2g-n-mGrfloor=0 $, $ lfloorfracn+mGrfloor=1 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
One thing you should be made aware of, however, is that when writing out proofs, you should avoid just writing down the equation you're trying to prove and manipulating it into something which is purportedly equivalent. The main reason why this is inadvisable is the that the flow of logic is wrong:
$$
left[matrixmboxProposition\ mboxto be provedright]implies P_2implies P_3implies dots impliesleft[matrixmboxTrue\ mboxPropositionright] ,$$
and the final proposition will be equivalent to the original only if every step in your manipulation is reversible. If that does happen to be true, then you will be able to reverse the implications in the above chain of propositions to obtain a valid proof:
$$
left[matrixmboxTrue\ mboxpropostionright]implies dots implies P_3implies P_2 impliesleft[matrixmboxProposition\ mboxto be provedright] ,$$
and this is the form which any proof you give should take.
As it turns out, your addition, $ "➕" $, is essentially the same thing as addition modulo $ b^r-1 $:
$$ a➕c equiv a+c pmodb^r-1 .$$
Your negation is also the same as negation modulo $ b^r-1 $:
$$ m'equiv -m pmodb^r-1 .$$
So your observation that $ n➕m= (n'➕m')' $ is equivalent to the equation:
$$ m+nequiv -left(left(-mright)+left(-nright)right) pmodb^r-1 ,$$
which is not difficult to prove using modular arithmetic.
$endgroup$
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
add a comment |
$begingroup$
You've done pretty well in your proof, which requires just one extra step.
If $ m+n le g-1 $, then $$ 2G>2gge 2g-n-m ge g+1= G .$$
Thus, since $ 2G>2g-n-mge G $ in this case, you have $ lfloorfrac2g-n-mGrfloor=1 $, $ lfloorfracn+mGrfloor=0 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
On the other hand, if $ m+n>g-1 $, then (because $ m,n < g $):
$$0<2g-n-m<g+1=G ,$$
and so $ lfloorfrac2g-n-mGrfloor=0 $, $ lfloorfracn+mGrfloor=1 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
One thing you should be made aware of, however, is that when writing out proofs, you should avoid just writing down the equation you're trying to prove and manipulating it into something which is purportedly equivalent. The main reason why this is inadvisable is the that the flow of logic is wrong:
$$
left[matrixmboxProposition\ mboxto be provedright]implies P_2implies P_3implies dots impliesleft[matrixmboxTrue\ mboxPropositionright] ,$$
and the final proposition will be equivalent to the original only if every step in your manipulation is reversible. If that does happen to be true, then you will be able to reverse the implications in the above chain of propositions to obtain a valid proof:
$$
left[matrixmboxTrue\ mboxpropostionright]implies dots implies P_3implies P_2 impliesleft[matrixmboxProposition\ mboxto be provedright] ,$$
and this is the form which any proof you give should take.
As it turns out, your addition, $ "➕" $, is essentially the same thing as addition modulo $ b^r-1 $:
$$ a➕c equiv a+c pmodb^r-1 .$$
Your negation is also the same as negation modulo $ b^r-1 $:
$$ m'equiv -m pmodb^r-1 .$$
So your observation that $ n➕m= (n'➕m')' $ is equivalent to the equation:
$$ m+nequiv -left(left(-mright)+left(-nright)right) pmodb^r-1 ,$$
which is not difficult to prove using modular arithmetic.
$endgroup$
You've done pretty well in your proof, which requires just one extra step.
If $ m+n le g-1 $, then $$ 2G>2gge 2g-n-m ge g+1= G .$$
Thus, since $ 2G>2g-n-mge G $ in this case, you have $ lfloorfrac2g-n-mGrfloor=1 $, $ lfloorfracn+mGrfloor=0 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
On the other hand, if $ m+n>g-1 $, then (because $ m,n < g $):
$$0<2g-n-m<g+1=G ,$$
and so $ lfloorfrac2g-n-mGrfloor=0 $, $ lfloorfracn+mGrfloor=1 $, and
$lfloorfrac2g-n-mGrfloor+lfloorfracn+mGrfloor=1 .$
One thing you should be made aware of, however, is that when writing out proofs, you should avoid just writing down the equation you're trying to prove and manipulating it into something which is purportedly equivalent. The main reason why this is inadvisable is the that the flow of logic is wrong:
$$
left[matrixmboxProposition\ mboxto be provedright]implies P_2implies P_3implies dots impliesleft[matrixmboxTrue\ mboxPropositionright] ,$$
and the final proposition will be equivalent to the original only if every step in your manipulation is reversible. If that does happen to be true, then you will be able to reverse the implications in the above chain of propositions to obtain a valid proof:
$$
left[matrixmboxTrue\ mboxpropostionright]implies dots implies P_3implies P_2 impliesleft[matrixmboxProposition\ mboxto be provedright] ,$$
and this is the form which any proof you give should take.
As it turns out, your addition, $ "➕" $, is essentially the same thing as addition modulo $ b^r-1 $:
$$ a➕c equiv a+c pmodb^r-1 .$$
Your negation is also the same as negation modulo $ b^r-1 $:
$$ m'equiv -m pmodb^r-1 .$$
So your observation that $ n➕m= (n'➕m')' $ is equivalent to the equation:
$$ m+nequiv -left(left(-mright)+left(-nright)right) pmodb^r-1 ,$$
which is not difficult to prove using modular arithmetic.
answered Apr 1 at 9:35
lonza leggieralonza leggiera
1,45728
1,45728
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Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
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– Patrik Bašo
Apr 1 at 10:29
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Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
add a comment |
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you man, I already solved it too , Then I will add my conclusion which is a little more easier I think, So would you look at it then?
$endgroup$
– Patrik Bašo
Apr 1 at 10:29
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
$begingroup$
Thank you for your answer,it really helped me ,
$endgroup$
– Patrik Bašo
Apr 1 at 10:34
add a comment |
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Your "bitwise negation" of a decimal number is called its nines' complement.
$endgroup$
– FredH
Mar 31 at 20:24