premise: Three construction workers smoothing new sidewalk cement in a city. hypothesis: constructions working put down new cement.
entailment: In the second sentence the outcome of the construction is described (cement) while in the first sentence we are told that the construction is carried out by three individuals and the cement is put down for the purpose of constructing a new sidewalk.   Someone needs to be doing the action before the action takes place. Hence sentence 2 follows sentence 1.