Exception for 2sqrt (example 3.1)

Math

\[\sqrt{x + 1} - \sqrt{x} \]

FPCore

(FPCore (x) :precision binary64 (- (sqrt (+ x 1.0)) (sqrt x)))

C

double code(double x) {
	return sqrt((x + 1.0)) - sqrt(x);
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((x + 1.0d0)) - sqrt(x)
end function

Java

public static double code(double x) {
	return Math.sqrt((x + 1.0)) - Math.sqrt(x);
}

Python

def code(x):
	return math.sqrt((x + 1.0)) - math.sqrt(x)

Julia

function code(x)
	return Float64(sqrt(Float64(x + 1.0)) - sqrt(x))
end

MATLAB

function tmp = code(x)
	tmp = sqrt((x + 1.0)) - sqrt(x);
end

Wolfram

code[x_] := N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022203 
(FPCore (x)
  :name "2sqrt (example 3.1)"
  :precision binary64

  :herbie-target
  (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x)))

  (- (sqrt (+ x 1.0)) (sqrt x)))

Backtrace

hash-ref: no value found for key key: '~		L	C
get-parametric-operator	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/syntax.rkt	218	0
f336	.../match/compiler.rkt	548	40
expand-parametric	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/sugar.rkt	62	0
(unnamed)	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt	176	8
generate-rules-for	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt	161	0
generate-missing-rules	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt	187	0
(unnamed)	/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt	29	26
get-swaps	/data/pavpan/nightlies/herbie/enumo-rat/src/symmetry.rkt	6	0
connected-components	/data/pavpan/nightlies/herbie/enumo-rat/src/symmetry.rkt	17	0
run-improve!	/data/pavpan/nightlies/herbie/enumo-rat/src/mainloop.rkt	296	0
(unnamed)	/data/pavpan/nightlies/herbie/enumo-rat/src/sandbox.rkt	55	6
(unnamed)	/usr/share/racket/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/share/racket/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/share/racket/collects/racket/engine.rkt	42	24