COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	.BEGIN CENTERITTABIT2(10,21)SELECT 1
C00004 ENDMK
C⊗;
.BEGIN CENTERIT;TABIT2(10,21);SELECT 1;

.GROUP;

II  Consider the following definition:

%3
\  twist[s] <=\[atom[s] → s;
\\ %et%* → cons[twist[cdr[s]];twist[car[s]]]]
  

%21%1. Is the function partial or is it total? Now evaluate: 

%22.%3 twist[A]   %23.%3 twist[(A . B)]   %24.%3 twist[((A . B) . C)]
.APART
.END
.BEGIN CENTERIT;TABIT2(10,23);SELECT 1;
.GROUP

%1
III  Now try:
%3
\findem[x;y] <=\[atom[x] → [eq[x;y] → T; %et%* → NIL];
\\ %et%* → cons[findem[car[x];y];findem[cdr[x];y]]]


%21%1.  Is this function total? Now evaluate:

←%22.%3 findem[(A . B);A]   %23.%3 findem[(B .(A . C));A]  
←%24.%3 findem[(B .(A . C));C]  %25.%3 findem[(A . B);(A . B)]
.APART

.END