Error in api.Select. Kindly help!

[infinite-pursuits]

I have the following circuit.

type verifyinference struct {
	Callweightsfull [numlayersconst + 1][inputsizeconst][inputsizeconst]frontend.Variable `gnark:"allweightsfull"`
	Callbiasesfull  [numlayersconst + 1][inputsizeconst]frontend.Variable                 `gnark:"allbiasesfull"`
	Cx              [inputsizeconst]frontend.Variable                                     `gnark:"Cx"`
	Cfout frontend.Variable `gnark:"coutput"`
}

func (circuit *verifyinference) Define(api frontend.API) error {
	var x [inputsizeconst]frontend.Variable
	var allweightsfull [numlayersconst + 1][inputsizeconst][inputsizeconst]frontend.Variable
	var allbiasesfull [numlayersconst + 1][inputsizeconst]frontend.Variable
	var tempinp [inputsizeconst]frontend.Variable
	var fieldsize frontend.Variable
	var minusone frontend.Variable
	allweightsfull = circuit.Callweightsfull
	allbiasesfull = circuit.Callbiasesfull
	x = circuit.Cx
	tempinp = x
	fieldsize = api.Compiler().Field()
	minusone = api.Sub(fieldsize, frontend.Variable(1))

	for hidden_layer := 0; hidden_layer < numlayersconst+1; hidden_layer++ {

		var dotpdtvec [inputsizeconst]frontend.Variable
		var biassum [inputsizeconst]frontend.Variable
		var postrelu [inputsizeconst]frontend.Variable
		var vals [inputsizeconst]frontend.Variable
		
		dotpdtvec = MulVecf(api, allweightsfull[hidden_layer], tempinp)
		biassum = AddVecf(api, dotpdtvec, allbiasesfull[hidden_layer])
		for i := 0; i < inputsizeconst; i++ {
			
			valsval := api.Div(minusone, frontend.Variable(2))
			vals[i] = api.Cmp(valsval, biassum[i])
			valcomp := api.IsZero(api.Sub(vals[i], minusone))
			postrelu[i] = api.Select(valcomp, frontend.Variable(0), biassum[i])

		}
		tempinp = postrelu
	}

	var output frontend.Variable
	var cmp frontend.Variable

	cmp = api.Cmp(tempinp[0], tempinp[1])
	output = api.Select(cmp, frontend.Variable(0), frontend.Variable(1))

	api.AssertIsEqual(output, circuit.Cfout)
	api.Println("Assert in verifyinf done")
	return nil
}

When I run the circuit, I see that the AssertIsEqual runs successfully and I am able to see "Assert in verifyinf done" printed. When cmp is -1, I see the value 2 -- which matches circuit.Cfout. Still, I see the following error. I think the error is coming from the last 5 lines. Kindly help me resolve.

22:27:17 ERR error="unsatisfied constraint" backend=groth16 id=166808 nbConstraints=166810
Error in Proving:  constraint #166808 is not satisfied: -1 ⋅ 2 != 0
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1367e99]

[ivokub]

Can you provide some example witness data for testing?