weird behaviour of .sp| with expression

[Ulrich Lauther]

Hi all,

look at this code:

      .nr t1 5c
      .nr t2 5c
      .nr foo1 \n[t1]u+\n[t2]u
      foo1 \n[foo1]
      
      .nr foo2 (\n[t1]+\n[t2])u
      foo2 \n[foo2]
      .sp |10c
      10 c
      .sp |\n[t1]u+\n[t2]u
                    no braket
      .sp |(\n[t1]+\n[t2])u
      with braket

It prints
      foo1 283464

      foo2 283464

so both esxpressions are evaluted to the same result.

Then it prints "10c  no bracket" on one line somewhere in the middle of my page.
But "with bracket" is printed o few lines below.

How come?

        -ulrich