• ← Sequence

Unevaluated

WMA link

Unevaluated[expr]

temporarily leaves expr in an unevaluated form when it
appears as a function argument.

Unevaluated is automatically removed when function arguments are
evaluated:

• • Sqrt[Unevaluated[x]]

• • Length[Unevaluated[1+2+3+4]]

Unevaluated has attribute HoldAllComplete:

• • Attributes[Unevaluated]

Unevaluated is maintained for arguments to non-executed functions:

• • f[Unevaluated[x]]

Likewise, its kept in flattened arguments and sequences:

• • Attributes[f] = {Flat};

• • f[a, Unevaluated[f[b, c]]]

• • g[a, Sequence[Unevaluated[b], Unevaluated[c]]]

However, unevaluated sequences are kept:

• • g[Unevaluated[Sequence[a, b, c]]]