Equality and Conditional
AutoLISP includes functions that provide equality verification as well as conditional branching and looping. The equality and conditional functions are listed in AutoLISP Function Synopsis under the heading Equality and Conditional Functions These functions are described in the AutoLISP Reference.
When writing code that checks string and symbol table names, keep in mind that AutoLISP automatically converts symbol table names to upper case in some instances. When testing symbol names for equality, you need to make the comparison insensitive to the case of the names. Use the strcase function to convert strings to the same case before testing them for equality.