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6 changes: 6 additions & 0 deletions contents/euclidean_algorithm/euclidean_algorithm.md
Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,12 @@ Here's a video on the Euclidean algorithm:
<iframe width="560" height="315" src="https://www.youtube.com/embed/h86RzlyHfUE" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</div>

## Proof

Some intuition as to why the Euclidean Algorithm works lies in it's proof. Only a proof for the subtraction method will be given at this point, but the modular version follows the same line of reasoning.
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Some intuition as to why the Euclidean Algorithm works lies in it's proof. Only a proof for the subtraction method will be given at this point, but the modular version follows the same line of reasoning.
Some intuition as to why the Euclidean Algorithm works lies in its proof. Only a proof for the subtraction method will be given at this point, but the modular version follows the same line of reasoning.


Given two positive integers $$a$$ and $$b$$, they have a greatest common divisor $$d$$. There is always a common divisor, because every number is divisable by 1. Since $$a$$ and $$b$$ is divisable by $$d$$, $$a - b$$ is also divisable by $$d$$ ($$b < a$$). Let's call this value $$c$$. Now we once more have two numbers $$b$$ and $$c$$, which are both divisable by $$d$$. This process can be continued until the values are equal: this is the greatest common divisor $$d$$.
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Given two positive integers $$a$$ and $$b$$, they have a greatest common divisor $$d$$. There is always a common divisor, because every number is divisable by 1. Since $$a$$ and $$b$$ is divisable by $$d$$, $$a - b$$ is also divisable by $$d$$ ($$b < a$$). Let's call this value $$c$$. Now we once more have two numbers $$b$$ and $$c$$, which are both divisable by $$d$$. This process can be continued until the values are equal: this is the greatest common divisor $$d$$.
Given two positive integers $$a$$ and $$b$$, they have a greatest common divisor $$d$$. There is always a common divisor, because every number is divisible by 1. Since $$a$$ and $$b$$ are divisible by $$d$$, $$a - b$$ is also divisible by $$d$$ ($$b < a$$). Let's call this value $$c$$. Now we once more have two numbers $$b$$ and $$c$$, which are both divisible by $$d$$. This process can be continued until the values are equal: this is the greatest common divisor $$d$$.

Also, what happens with the edge case b=0, since you haven't talked about it, and it's not been discussed in the chapter yet?


## Example Code

{% method %}
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