<P>Most programming languages are TYPED, i.e., the sets of their computed values are SPLIT into subsets, termed types, that collect TOGETHER values of a similar KIND. In the part of Scheme that we study:

Computed_values = {Numbers, Booleans, Symbols, P rocedures, T uples}

where
Numbers = {1, 2, 5.1,−3, ....}
Booleans = {#t, #f}
Symbols = {a, ab1, moshe, ...}

P rocedures = set of all primitive procedures and closures over values, which is internally split into 1-ary closures from numbers to numbers, 2-ary closures from number pairs to closures, etc.

T uples = set of all tuples of values, which is internally split into pairs of numbers, pairs of closures, triplets, quadruples of values, etc.

Most programming languages are typed, i.e., the sets of their computed values are split into subsets, termed types, that collect together values of a similar kind. In the part of Scheme that we study:

Computed_values = {Numbers, Booleans, Symbols, P rocedures, T uples}

where
Numbers = {1, 2, 5.1,−3, ....}
Booleans = {#t, #f}
Symbols = {a, ab1, moshe, ...}

P rocedures = set of all primitive procedures and closures over values, which is internally split into 1-ary closures from numbers to numbers, 2-ary closures from number pairs to closures, etc.

T uples = set of all tuples of values, which is internally split into pairs of numbers, pairs of closures, triplets, quadruples of values, etc.