• Summary
• Acknowledgments
• Getting Started


• Overview of Scheme
• Lexical conventions
• Basic concepts
• Expressions
• Program structure
• Standard procedures


• Haskell Interface


• Standard Libraries
• Husk Libraries
• Standard Feature Identifiers
• Index

Disjointness of types

No object satisfies more than one of the following predicates:

These predicates define the types boolean, bytevector, character, the empty list object, eof-object, number, pair, port, procedure, string, symbol, vector, and all record types.

Although there is a separate boolean type, any Scheme value can be used as a boolean value for the purpose of a conditional test. As explained in section 6.3, all values count as true in such a test except for #f. This report uses the word "true" to refer to any Scheme value except #f, and the word "false" to refer to #f.