• Hold[expr] maintains expr in an unevaluated form.
has attribute HoldAll
, and performs no operation on its arguments.
• Example: Hold[1+1]
• Hold[, ,
maintains a sequence of unevaluated expressions to which a function can be applied using Apply
• Even though expr itself is not evaluated, Hold[expr] may still evaluate if expr is of the form f[args], and upvalues for f have been defined.
• New in Version 1.