is an attribute which specifies that the first argument to a function should not be affected by N.


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Basic Examples  (1)

Prevent N from affecting the first argument of a function:

Scope  (2)

System symbols with the NHoldFirst attribute:

The ^(th) zero of the zeta function on the critical line with the imaginary part greater than :

N does not affect the index :

When the second argument is numeric, N evaluates numerically:

Applications  (1)

Define an "inverse" for :

Set the NHoldFirst attribute so that remains an integer:

A symbolic representation of an inverse of :

This remains unmodified with N:

With a numeric value of x, the function binv evaluates numerically:

Properties & Relations  (1)

HoldFirst prevents evaluation while NHoldFirst only prevents numerical evaluation:

You can prevent both by setting both attributes:

Introduced in 1996