# Euclid’s first postulate

To draw a straight line from any point to any point.

A postulate, to quote from dictionary.com is something taken as self-evident or assumed without proof as a basis for reasoning. And according to Euclid, nothing can be more self-evident than the fact that given two points, one can draw a straight line segment joining them.

Now, it is also obviously self-evident that there is exactly one such line joining two given points, i.e. that there is a unique line joining any two points.

However Euclid does not mention the uniqueness, though he seems to assume it in the subsequent proofs .. So probably a more accurate first postulate would be

To draw a straight line (which will be unique) from any point to any point.

The Processing code

```int time1 = 500;
int time2 = 2500;
PFont f;

void setup() {
size(600, 120);
smooth();
f = createFont("Arial",20,true);
}
void draw() {
int currentTime = millis();
background(204);
if (currentTime > time2) {
ellipse(100,60,10,10);
text("A",95,90);
fill(0);
ellipse(500,60,10,10);
text("B",495,90);
line(100,60,500,60);
} else if (currentTime > time1) {
textFont(f,20);
fill(0);
ellipse(100,60,10,10);
text("A",95,90);
fill(0);
ellipse(500,60,10,10);
text("B",495,90);}

}
```