A.13.5 Between Versions 4 and 5

• 44 completely new built-in objects have been added, some of whose names may conflict with names already being used.
• Precision and Accuracy now return exact measures of uncertainty in numbers, not just estimates of integer numbers of digits.
• Precision now returns the symbol MachinePrecision for machine numbers, rather than the numerical value $MachinePrecision.
• N[expr, MachinePrecision] is now used for numerical evaluation with machine numbers; N[expr, $MachinePrecision] generates arbitrary-precision numbers.
• ConstrainedMin and ConstrainedMax have been superseded by Minimize, Maximize, NMinimize and NMaximize.
• SingularValues has been superseded by SingularValueList and SingularValueDecomposition. SingularValueDecomposition uses a different and more complete definition.
• LUBackSubstitution has been superseded by the use of the more general LinearSolveFunction.
• FindRoot[f, {x, {, }}] is now used to specify a starting vector value for x, rather than a pair of values. The same is true for FindMinimum.
• DSolveConstants has been superseded by the more general option GeneratedParameters.
• TensorRank has been replaced by ArrayDepth.
• $TopDirectory has been superseded by $InstallationDirectory and $BaseDirectory.
• The default setting for the MathLink LinkProtocol option when connecting different computer systems is now "TCPIP" rather than "TCP".