How to get a graphical representation of my graph's uncertainty due to RIFs?

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This is my worksheet: https://cocalc.com/share/f7766c5e-2f4...

I have a plot and subs some numerical values into it, and would love two or three lines, showing the range of uncertainty and perhaps the medium line of my plot.

i do this

plot( p_ges_rhs.subs( 
       d_e == RIF(.999,1.001), 
                d_k == 1, 
                d_m == RIF(.05,.15), 
                U == RIF(1e-9,1.1e-9), 
                e_m == e_0 * RIF(80.5,81.5), 
                e_s == e_0 * RIF(3,4) 
               ), ( x,0.01,.99 ) )

and get only the middle line (i guess).

can i get the three-line plot i described, or even just a two line plot? or are there other good ways to show the range of uncertainty?