Discrete uniform distribution (cumulative distribution function). Generated with the following R code:

library(latex2exp)
svg(file="Dis_Uniform_distribution_CDF.svg",width=4,height=3,pointsize=12)

par(mar=c(3,3,1,1))

n <- 5
plot(c(0,n+1),c(0,1),type="n", xaxt = "n", yaxt="n", ylab = "")
lines(c(-1,1),rep(0,2),col="blue")
for(x in n:0)
{
  lines(c(x,x+1),rep(x/n,2),col="blue")
  if (x>0)
  {
    points(x,(x-1)/n,col="white",pch=19)
    points(x,(x-1)/n,col="blue",pch=21)
    points(x,x/n,col="blue",pch=19)
  }
}
lines(c(n,n+2),rep(1,2),col="blue")
axis(side = 1, at = c(1,n), labels = c("a","b"))
axis(side = 2, at = c(0,ceiling(n/2)/n,1), labels = c(0,TeX("\\frac{i}{n}"),1),las=1)

dev.off()