C4_W1_Ungraded_Lab_4_Stack_Semantics

Course Q&A Natural Language Processing NLP with Attention Models
1

Is the explanation in " 3. The tl.Residual combinator in the context of the serial combinator" correct?

The tl.Residual doc said the Residual layer computes the element-wise sum of the stack-top input with the output of the layer series. Earlier in the notebook, it said " the rightmost element in the second column represents the top of the stack". However in the chart and the description, it said “This means the duplicate inputs (i.e. the 2 rightmost arrows of the Select outputs in the figure above) remain in the stack”. The 1st right most is the stack-top, followed by the 2nd right most. So the addition() layer should apply to the right half of the chart, not the left, right?

2

Hi April,

As a belated reply: you are right in that the chart is not consistent with the portrayal of the stack in the earlier tables. The bottom of the chart indicates that for the chart the stack top is on the left. To be consistent with the tables, the chart should have been mirrored.