maybe we should add in the error message that it should be a full height slope?
I think the error messages come from a part of the system that does not know about half/full versus single/double.
The 4 artificial walls from left to right go...
0.5, 1, 1.5, 2.
This might just confuse Argelle, but I add this for completeness: if the same tools were used in a double-height pak set, like pak64, you would get 1, 2, 3, 4, respectively.
The two ramps pointed by arrows from left to right...
0.5 slope, 1 slope
The other composite ramps are made out of artificial walls and slopes so have no real name.
In essence, they are, from lower left to upper right, four consecutive half-height slopes and two consecutive full-height slopes. Using the same tools in pak64, they would have been four consecutive single-height slopes and two consecutive double-height slopes.