diff --git a/README.md b/README.md
index bfac522..5f2a46e 100644
--- a/README.md
+++ b/README.md
@@ -3,9 +3,14 @@
 zkSNARK library implementation in Go
 
 
+- `Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture`, Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza https://eprint.iacr.org/2013/879.pdf
+- `Pinocchio: Nearly practical verifiable computation`, Bryan Parno, Craig Gentry, Jon Howell, Mariana Raykova https://eprint.iacr.org/2013/279.pdf
+
+## Caution
+Implementation from scratch in Go to understand the concepts. Do not use in production.
+
+Not finished, implementing this in my free time to understand it better, so I don't have much time.
 
-`Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture`, Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza https://eprint.iacr.org/2013/879.pdf
-`Pinocchio: Nearly practical verifiable computation`, Bryan Parno, Craig Gentry, Jon Howell, Mariana Raykova https://eprint.iacr.org/2013/279.pdf
 
 ### Usage
 - [![GoDoc](https://godoc.org/github.com/arnaucube/go-snark?status.svg)](https://godoc.org/github.com/arnaucube/go-snark) zkSnark
@@ -79,7 +84,5 @@ go test ./... -v
 
 ---
 
-## Caution
-Not finished, work in progress (implementing this in my free time to understand it better, so I don't have much time).
 
-Thanks to [@jbaylina](https://github.com/jbaylina), [@bellesmarta](https://github.com/bellesmarta), [@adriamb](https://github.com/adriamb) for their explanations that helped to understand this a little bit.
+Thanks to [@jbaylina](https://github.com/jbaylina), [@bellesmarta](https://github.com/bellesmarta), [@adriamb](https://github.com/adriamb) for their explanations that helped to understand this a little bit. Also thanks to [@vbuterin](https://github.com/vbuterin) for all the published articles explaining the zkSNARKs.
diff --git a/bn128/g1_test.go b/bn128/g1_test.go
index e2bf533..1c38337 100644
--- a/bn128/g1_test.go
+++ b/bn128/g1_test.go
@@ -1,10 +1,10 @@
 package bn128
 
 import (
+	"encoding/hex"
 	"math/big"
 	"testing"
 
-	"github.com/arnaucube/cryptofun/utils"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -26,6 +26,6 @@ func TestG1(t *testing.T) {
 	a := bn128.G1.Affine(grsum1)
 	b := bn128.G1.Affine(grsum2)
 	assert.Equal(t, a, b)
-	assert.Equal(t, "0x2f978c0ab89ebaa576866706b14787f360c4d6c3869efe5a72f7c3651a72ff00", utils.BytesToHex(a[0].Bytes()))
-	assert.Equal(t, "0x12e4ba7f0edca8b4fa668fe153aebd908d322dc26ad964d4cd314795844b62b2", utils.BytesToHex(a[1].Bytes()))
+	assert.Equal(t, "2f978c0ab89ebaa576866706b14787f360c4d6c3869efe5a72f7c3651a72ff00", hex.EncodeToString(a[0].Bytes()))
+	assert.Equal(t, "12e4ba7f0edca8b4fa668fe153aebd908d322dc26ad964d4cd314795844b62b2", hex.EncodeToString(a[1].Bytes()))
 }
diff --git a/circuitcompiler/circuit.go b/circuitcompiler/circuit.go
index a70ce2b..3f2e14a 100644
--- a/circuitcompiler/circuit.go
+++ b/circuitcompiler/circuit.go
@@ -1,10 +1,32 @@
 package circuitcompiler
 
+import (
+	"fmt"
+	"math/big"
+)
+
 type Circuit struct {
 	NVars       int
 	NPublic     int
 	NSignals    int
-	Inputs      []int
-	Witness     []int
+	Inputs      []string
+	Signals     []string
+	Witness     []*big.Int
 	Constraints []Constraint
+	R1CS        struct {
+		A [][]*big.Int
+		B [][]*big.Int
+		C [][]*big.Int
+	}
+}
+
+func (c *Circuit) GenerateR1CS() {
+	fmt.Print("function with inputs: ")
+	fmt.Println(c.Inputs)
+	fmt.Print("signals: ")
+	fmt.Println(c.Signals)
+	for _, constraint := range c.Constraints {
+		fmt.Println(constraint.Literal)
+
+	}
 }
diff --git a/circuitcompiler/circuit_test.go b/circuitcompiler/circuit_test.go
index 70decd9..b61d8a8 100644
--- a/circuitcompiler/circuit_test.go
+++ b/circuitcompiler/circuit_test.go
@@ -21,16 +21,22 @@ func TestCircuitParser(t *testing.T) {
 			m3 = m2 + s1
 			out = m3 + 5
 	*/
-	raw := `
-	y = x^x
-	z = x + y
-	out = z + 5
+
+	// flat code
+	flat := `
+	func test(x):
+		aux = x*x
+		y = aux*x
+		z = x + y
+		out = z + 5
 	`
-	parser := NewParser(strings.NewReader(raw))
-	res, err := parser.Parse()
+	parser := NewParser(strings.NewReader(flat))
+	circuit, err := parser.Parse()
 	assert.Nil(t, err)
-	fmt.Println(res)
+	fmt.Println(circuit)
 
-	// flat code
 	// flat code to R1CS
+	fmt.Println("generating R1CS from flat code")
+	circuit.GenerateR1CS()
+	fmt.Println(circuit.Inputs)
 }
diff --git a/circuitcompiler/parser.go b/circuitcompiler/parser.go
index 033d2d4..972fd7b 100644
--- a/circuitcompiler/parser.go
+++ b/circuitcompiler/parser.go
@@ -3,6 +3,8 @@ package circuitcompiler
 import (
 	"errors"
 	"io"
+	"regexp"
+	"strings"
 )
 
 type Parser struct {
@@ -17,10 +19,12 @@ type Parser struct {
 type Constraint struct {
 	// v1 op v2 = out
 	Op      Token
-	V1      Token
-	V2      Token
-	Out     Token
+	V1      string
+	V2      string
+	Out     string
 	Literal string
+
+	Inputs []string // in func delcaration case
 }
 
 func NewParser(r io.Reader) *Parser {
@@ -57,36 +61,72 @@ func (p *Parser) ParseLine() (*Constraint, error) {
 		in this version,
 		line will be for example s3 = s1 * s4
 		this is:
-		val op val op val
-		ident op ident op ident
+		val eq val op val
 	*/
 	c := &Constraint{}
-	var lit string
-	c.Out, lit = p.scanIgnoreWhitespace()
+	tok, lit := p.scanIgnoreWhitespace()
+	c.Out = lit
 	c.Literal += lit
+
+	if c.Literal == "func" {
+		// format: `func name(in):`
+		line, err := p.s.r.ReadString(':')
+		if err != nil {
+			return c, err
+		}
+		// read string inside ( )
+		rgx := regexp.MustCompile(`\((.*?)\)`)
+		insideParenthesis := rgx.FindStringSubmatch(line)
+		varsString := strings.Replace(insideParenthesis[1], " ", "", -1)
+		c.Inputs = strings.Split(varsString, ",")
+		return c, nil
+	}
+
 	_, lit = p.scanIgnoreWhitespace() // skip =
 	c.Literal += lit
-	c.V1, lit = p.scanIgnoreWhitespace()
+
+	// v1
+	_, lit = p.scanIgnoreWhitespace()
+	c.V1 = lit
 	c.Literal += lit
+	// operator
 	c.Op, lit = p.scanIgnoreWhitespace()
 	c.Literal += lit
-	c.V2, lit = p.scanIgnoreWhitespace()
+	// v2
+	_, lit = p.scanIgnoreWhitespace()
+	c.V2 = lit
 	c.Literal += lit
-	if c.Out == EOF {
+	if tok == EOF {
 		return nil, errors.New("eof in parseline")
 	}
 	return c, nil
 }
 
+func addToArrayIfNotExist(arr []string, elem string) []string {
+	for _, v := range arr {
+		if v == elem {
+			return arr
+		}
+	}
+	arr = append(arr, elem)
+	return arr
+}
 func (p *Parser) Parse() (*Circuit, error) {
 	circuit := &Circuit{}
+	circuit.Signals = append(circuit.Signals, "one")
 	for {
 		constraint, err := p.ParseLine()
 		if err != nil {
-			// return circuit, err
 			break
 		}
+		if constraint.Literal == "func" {
+			circuit.Inputs = constraint.Inputs
+			continue
+		}
 		circuit.Constraints = append(circuit.Constraints, *constraint)
+		circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.V1)
+		circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.V2)
+		circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.Out)
 	}
 	return circuit, nil
 }
diff --git a/go.mod b/go.mod
index 6bc629d..3593c67 100644
--- a/go.mod
+++ b/go.mod
@@ -1,7 +1,6 @@
 module github.com/arnaucube/go-snark
 
 require (
-	github.com/arnaucube/cryptofun v0.0.0-20181210231954-f5d913b6a74c
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.2.2
diff --git a/go.sum b/go.sum
index a6c76b7..e03ee77 100644
--- a/go.sum
+++ b/go.sum
@@ -1,9 +1,3 @@
-github.com/arnaucube/bn128 v0.0.0-20181124004642-3bb6b68ddbe4/go.mod h1:bIKGJe1ZaHy7HYQML7Me4q38pOpggn3JO1VPPyMe3zI=
-github.com/arnaucube/cryptofun v0.0.0-20181124001128-d55d875d7a54/go.mod h1:PZE8kKpHPD1UMrS3mTfAMmEEinGtijSwjxLRqRcD64A=
-github.com/arnaucube/cryptofun v0.0.0-20181124004321-9b11ae8280bd/go.mod h1:PZE8kKpHPD1UMrS3mTfAMmEEinGtijSwjxLRqRcD64A=
-github.com/arnaucube/cryptofun v0.0.0-20181210231954-f5d913b6a74c h1:i0PwrCdHaQXw6KhbIS+VVj1x/GmqHgOs/LCXLeevE3c=
-github.com/arnaucube/cryptofun v0.0.0-20181210231954-f5d913b6a74c/go.mod h1:jLYDEjM/9/Q/bpdj+9ZdKh2qDIgS2gqcywjg+93MyGI=
-github.com/arnaucube/go-snark v0.0.0-20181207210027-19f7216d0e3d/go.mod h1:gLycS/B43DufBaH0jH8kqiE4A7w5FdOM8I9S416xh2Y=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=