===== 7.1 Assumptions: The Meaning of "Must" =====

The description of each instruction is always given in the context of Java Card virtual machine code that satisfies the static and structural constraints of [[6._The_CAP_File_Format| Chapter 6]], "The CAP File Format". 

In the description of individual Java Card virtual machine instructions, we frequently state that some situation "must" or "must not" be the case: "The value2 must be of type int." The constraints of [[6._The_CAP_File_Format| Chapter 6]] "The CAP File Format" guarantee that all such expectations will in fact be met. If some constraint (a "must" or "must not") in an instruction description is not satisfied at run time, the behavior of the Java Card virtual machine is undefined.