My page on lambda diagrams at http://www.cwi.nl/~tromp/cl/diagrams.html http://www.cwi.nl/~tromp/cl/diagrams.html has a nice picture of the Y-combinator at th

My page on lambda diagrams at http://www.cwi.nl/~tromp/cl/diagrams.html http://www.cwi.nl/~tromp/cl/diagrams.html has a nice picture of the Y-combinator at the top, and this note at the bottom: The diagram in the title, produced by the postscript code below, is a slightly deformed alternative Y diagram made to look like a Y. %!PS-Adobe-2.0 EPSF-2.0 %%BoundingBox:0 0 118 110 /m{moveto}def/l{lineto}def/c{concat 6 m 0 6 l 7 8 m 0 8 l l l 3 6 l 2 6 m 7 6 l 3 4 m 6 4 l 6 6 l stroke}def 3 0 0 0 1[-8 4 0 8 60 9]c 3 2 0 2 2[-1 1 0 1 0 0]c