.DEVICE XGP
.FONT 4 "BASB30"
.FONT 3 "BASI30"
.FONT 2 "BDR30"
.FONT 1 "BDR30"
.EVENLEFTBORDER←ODDLEFTBORDER←1000
.PAGE FRAME 52 HIGH 83 WIDE;
.AREA TEXT LINES 4 TO 50;
.TITLE AREA HEADING LINES 1 TO 3;
.PLACE TEXT;
.EVERY HEADING(,,{PAGE});
.BEGIN NOFILL
.VARIABLE CHW
.CHW ← CHARW
.TURN OFF "βα#\←∞↑↓∪"
.TURN ON "∂{%"
.TURN ON "/" FOR "α"
.AT "∂∂(" CH ")" ⊂ CHARW←CH}∂(2){CHARW←CHW ⊃


∂∂(48)%3transform%2[%3e%2, %3r%2, %3done%2] ← 
∂∂(80)%4if%2 %3e%2 ε %3done%2 %4then%2 %3e
∂∂(80)%4else%2 /{%3transa%2[%3e%2, %3r%2]}[λ%3w%2. 
∂∂(112)%4if%2 %3w%2 %4eq %3e%2 %4then%2 
∂∂(144)[%4if%2 %4at %3e%2 %4then%2 %3e
∂∂(153)%4else%2 /{%3transform%2[%4a %3e%2, %3r%2, %3done%2], %3transform%2[%4d %3e%2, %3r%2, %3done%2]}[λ%3x%2, %3y%2. 
∂∂(185)%4if%2 %3x%2 %4eq a %3e%2 ∧ %3y%2 %4eq d %3e%2 %4then%2 %3side%2[%3e%2, %3done%2 ← %3e%2 . %3done%2] %4else%2 %3transform%2[%3x%2 . %3y%2, %3r%2, %3done%2]]]
∂∂(112)%4else%2 %3transform%2[%3w%2, %3r%2, %3done%2]]



∂∂(48)%3transa%2[%3e%2, %3r%2] ← %4if%2 %4n %3r%2 %4then%2 %3e%2 %4else%2 /{%3transb%2[%3e%2, %4a %3r%2]}[λ%3w%2. %4if%2 %3w%2 %4eq %3e%2 %4then%2 %3transa%2[%3e%2, %4d %3r%2] %4else%2 %3w%2]



∂∂(48)%3transb%2[%3e%2, %3rule%2] ← /{%3inst%2[%3e%2, %4a %3rule%2, NIL]}[λ%3w%2. %4if%2 %3w%2 %4eq %2NO %4then%2 %3e%2 %4else%2 %3sublis%2[%4ad %3rule%2, %3w%2]]



∂∂(48)%3side%2[%3x%2, %3y%2] ← %3x

.END