| unAnnotate | Util.Annotated |
| unaryBooleanExpression | CSPM.DataStructures.Syntax, CSPM |
| UnaryBooleanOp | CSPM.DataStructures.Syntax, CSPM |
| unaryBooleanOpOperator | CSPM.DataStructures.Syntax, CSPM |
| UnaryMathsOp | CSPM.DataStructures.Syntax, CSPM |
| UnCompiledOperator | CSPM.Evaluator.ProcessValues, CSPM.Evaluator |
| UnCompiledProc | CSPM.Evaluator.ProcessValues, CSPM.Evaluator |
| UnCompiledProcOperator | CSPM.Evaluator.ProcessValues, CSPM.Evaluator |
| unCSPM | CSPM |
| unDotProduct | CSPM.Evaluator.ValueSet, CSPM.Evaluator |
| unificationErrorMessage | CSPM.TypeChecker.Exceptions |
| unificationStack | CSPM.TypeChecker.Monad |
| unify | CSPM.TypeChecker.Unification |
| unifyAll | CSPM.TypeChecker.Unification |
| union | CSPM.Evaluator.ValueSet, CSPM.Evaluator |
| unions | CSPM.Evaluator.ValueSet, CSPM.Evaluator |
| Unknown | Util.Annotated |
| unknownConstraintError | CSPM.Parser.Exceptions |
| unmarkDatatypeAsComparableForEquality | CSPM.TypeChecker.Monad |
| UnQual | CSPM.DataStructures.Names, CSPM |
| UnRenamedName | CSPM.DataStructures.Names, CSPM |
| unRenamedNameMemberName | CSPM.DataStructures.Names, CSPM |
| unRenamedNameModuleName | CSPM.DataStructures.Names, CSPM |
| unsafeNameUsed | CSPM.TypeChecker.Exceptions |
| unusedTypeAnnotationsError | CSPM.Parser.Exceptions |
| update | |
| 1 (Function) | Util.HierarchicalMap |
| 2 (Function) | CSPM.TypeChecker.Environment |
| updateMulti | Util.HierarchicalMap |
| updateParentScopeIdentifier | CSPM.Evaluator.Monad |
| updatePF | Util.PartialFunctions |
| UProc | CSPM.Evaluator.Values, CSPM.Evaluator, CSPM |
| UProcOperator | CSPM.Evaluator.Values, CSPM.Evaluator, CSPM |
| UserError | Util.Exception |
| UserEvent | CSPM.Evaluator.ProcessValues, CSPM.Evaluator.Values, CSPM.Evaluator, CSPM |