0 too outrageous to be considered -- nemyslitelný
It would be unthinkable to ask him to do that.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Můžeme to dokončit krok za krokem, ať je cesta jakkoli dlouhá, a nelze ji dokončit, ať je cesta jakkoli krátká, pokud si ani neoznačíte svou stopu.