|   | CMU-CS-97-125 Computer Science Department
 School of Computer Science, Carnegie Mellon University
 
    
     
 CMU-CS-97-125
 
A Linear Spine Calculus 
Iliano Cervesato, Frank Pfenning 
April 1997  
CMU-CS-97-125.ps Keywords: Linear lambda calculus, abstract Bohm trees, term assignment
systems, uniform provability
 We present the spine calculus S-> -o&T as an
efficient representation for the linear lambda-calculus 
lambda -> -o&T which includes intuitionistic functions
(->), linear functions - o , additive pairing (&), and additive 
unit T. S-> -o&T enhances the representation of Church's 
simply typed lambda-calculus as abstract Bohm trees by enforcing extensionality
and by incorporating linear constructs.  This approach permits procedures
such as unification to retain the efficient head access that characterizes
first-order term languages without the overhead of performing
n-conversions at run time.  Potential applications lie in proof search,
logic programming, and logical frameworks based on linear type theories. We 
define the spine calculus, give translations of lambda -> -o&T 
into S -> -o&T  and vice-versa, prove their soundness
and completeness with respect to typing and reductions, and show that the
spine calculus is strongly normalizing and admits unique canonical forms.
36 pages
 
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