max

[procedure] max x1 x2 ...

[procedure] min x1 x2 ...

R5RS, R6RS

Note: R6RS states that, for any real number object x,

 (max +inf.0 x) => +inf.0
 (min -inf.0 x) => -inf.0

Therefore, (max +inf.0 +nan.0) => +inf.0.