With his mohawk and sunglasses, Josh looked really dudical.

Fiords are glacially carved oceanic intrusions into land. They are often deep and narrow with a sill in the mouth. Waters from neighboring seas and locally supplied fresh water fill up the fiords, often leading to strong stratification. Fiords with tidewater glaciers also contain glacial ice. During transport into and stay in the fiord, mixing processes modify the properties of imported water masses.

We call them slack variables because they pick up the slack, so to speak; that is, they take on whatever values are necessary to create equalities (notice that each slack variable must be nonnegative).

If you get a last-minute dinner invitation, you might freeze that fish you bought; if you take the kids strawberry picking, get the excess in there as quickly as you can; if you have a superharvest of vegetables (or a good score at the farmer’s market), blanch them and freeze them.