We study the strict type assignment system, a restriction of the 
intersection type discipline \cite {Barendregt-et.al'}, and prove 
that it has the principal type property.  We define, for a term 
$M$, the principal pair (of basis and type).  We specify three 
operations on pairs, and prove that all pairs deducible for $M$ 
can be obtained from the principal one by these operations, and 
that these map deducible pairs to deducible pairs.



Appeared as:

@Article {Bakel-JLC'93,
Author =        "S. van Bakel",
Title =         "Principal type schemes for the {S}trict {T}ype 
		{A}ssignment {S}ystem",
Journal =       "Logic and Computation",
Volume =        "3",
Number =        "6",
Year =          "1993",
Pages =         "643-670"
}