\[0 \leq s \land s \leq 1.0651631\]
\[\frac{1}{1 + e^{\frac{-x}{s}}} \]
(FPCore (x s) :precision binary32 (/ 1.0 (+ 1.0 (exp (/ (- x) s)))))
float code(float x, float s) {
	return 1.0f / (1.0f + expf((-x / s)));
}
real(4) function code(x, s)
    real(4), intent (in) :: x
    real(4), intent (in) :: s
    code = 1.0e0 / (1.0e0 + exp((-x / s)))
end function
function code(x, s)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-x) / s))))
end
function tmp = code(x, s)
	tmp = single(1.0) / (single(1.0) + exp((-x / s)));
end
\frac{1}{1 + e^{\frac{-x}{s}}}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022150 
(FPCore (x s)
  :name "Logistic function"
  :precision binary32
  :pre (and (<= 0.0 s) (<= s 1.0651631))
  (/ 1.0 (+ 1.0 (exp (/ (- x) s)))))

Backtrace

application: required keyword argument not supplied procedure: batch-egg-rewrite required keyword: #:rules arguments...: '(#<rule erfc-erf_binary32> #<rule erf-erfc_binary32> #<rule erf-odd_binary32> #<rule prod-diff_binary32> #<rule hypot-udef_binary32> #<rule expm1-log1p-u_binary32> #<rule log1p-expm1-u_binary32> #<rule log1p-udef_binary32> #<rule expm1-udef_binary32> #... #:depths '(1 1 1) #:roots '((2) (2) (2))LC
(unnamed)/opt/racket-8.1/collects/racket/private/kw.rkt155814
rewrite-expressions/data/pavpan/nightlies/herbie/timeline/src/core/matcher.rkt1710
gen-rewrites!/data/pavpan/nightlies/herbie/timeline/src/patch.rkt1440
patch-table-run/data/pavpan/nightlies/herbie/timeline/src/patch.rkt2910
(unnamed)/opt/racket-8.1/collects/racket/contract/private/arrow-val-first.rkt48618
run-iter!/data/pavpan/nightlies/herbie/timeline/src/mainloop.rkt2460
mutate!/data/pavpan/nightlies/herbie/timeline/src/mainloop.rkt3790
run-improve!/data/pavpan/nightlies/herbie/timeline/src/mainloop.rkt3260
(unnamed)/data/pavpan/nightlies/herbie/timeline/src/sandbox.rkt666
(unnamed)/opt/racket-8.1/share/pkgs/profile-lib/main.rkt4010
profile-thunk/opt/racket-8.1/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-8.1/collects/racket/engine.rkt4224