Portability  portable 

Stability  experimental 
Maintainer  divip@aszt.inf.elte.hu 
Lazy Peano numbers including observable infinity value.
Note that the following equation does not hold for this number type:

1 + a > a
, because1 + infinity == infinity
.
The following operation is undefined:
infinity  infinity
There are variants of ()
with different behaviour regarding this, see below.
The following operations are naturally undefined:
fromEnum infinity
toInteger infinity

0  n
, ifn > 0

fromInteger n
, ifn < 0

toEnum n
, ifn < 0
pred 0
Documentation
Natural numbers and infinity.
Difference of two natural numbers: the result is either positive or negative.
Variant of diff
: zeroDiff infinity infinity == Left 0
.
Variant of diff
: infDiff infinity infinity == Left infinity
.