x = τ(r+1) - τr = τ(r+1-r) = τ(1) = τ
https://docs.python.org/3/library/math.html#math.tau
https://www.google.com/search?q=tau*1
https://docs.oracle.com/en/java/javase/21/docs/api/java.base...
https://learn.microsoft.com/en-us/dotnet/api/system.math.tau...
https://en.wikipedia.org/wiki/Tau
x = τ(r+1) - τr = τ(r+1-r) = τ(1) = τ