# Difference between U and U(t)

If I have

```
t = var('t')
U = function('U', t).function(t)
```

what is the difference between the expression *U* and *U(t)*. When should I use which?

Difference between U and U(t)

If I have

```
t = var('t')
U = function('U', t).function(t)
```

what is the difference between the expression *U* and *U(t)*. When should I use which?

0

Asked: **
2011-07-30 13:38:30 -0500
**

Seen: **108 times**

Last updated: **Sep 16 '11**

A simple problem related to symbolic calculation

Type changing after substitution

Substitute formal function by an expression in a differential equation

Defining a function of the form $f(x_1,x_2,...,x_n)=\sum_{i=0}^n x_i$

Printing (large) symbolic matrices

Substituting for a matrix of variables

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