| ||
本文作者:YEUNGCHIE
本文连接:https://www.cnblogs.com/yeungchie/p/12823609.html
## code
```
unless(fboundp('HowFar)
procedure(HowFar(a b)
prog(()
return(sqrt((xCoord(a) - xCoord(b)) ** 2 (yCoord(a) - yCoord(b)) ** 2))
)
)
)
```
## example
```
HowFar(0:0 1:1)
=>1.414214
```