Answer the following question based on the information given below.
For a real number $x,$ let
f(x)
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= 1/(1 + x),
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if x is non-negative
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= 1+ x,
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if x is negative
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f$^n$(x)
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= f(f$^{n – 1}$(x)), n = 2, 3, ....
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$r$ is an integer $\geq 2.$ Then what is the value of $f^{r-1}(-r) + f^r(-r)+f^{r+1}(-r)$?
- $-1$
- $0$
- $1$
- None of these