Usage
# S3 method for tpp
plot(x,xlab="time",ylab="",main = "cumulative number",...)
# S3 method for tppint
plot(x,xlab=xlab,xlim=xlim,line=2.5,main="NULL",...)
# S3 method for tpp
print(x,...)
# S3 method for tppint
print(x,...)
# S3 method for tpp
[(x,i)
# S3 method for tppint
[(x,i)