diff --git a/src/mmath/bigint.nim b/src/mmath/bigint.nim
index 8648114..4e1e406 100644
--- a/src/mmath/bigint.nim
+++ b/src/mmath/bigint.nim
@@ -260,3 +260,6 @@ proc `>`*(n1 : BigInt, n2 : BigInt) : bool = cmp(n1, n2) > 0
 proc `==`*(n1 : BigInt, n2 : BigInt) : bool = cmp(n1, n2) == 0
 proc `<=`*(n1 : BigInt, n2 : BigInt) : bool = cmp(n1, n2) <= 0
 proc `>=`*(n1 : BigInt, n2 : BigInt) : bool = cmp(n1, n2) >= 0
+proc `!=`*(n1 : BigInt, n2 : BigInt) : bool = cmp(n1, n2) != 0
+
+proc `of`*(_ : typedesc[BigInt], n : int64) : BigInt = newBigInt(n)
\ No newline at end of file
diff --git a/src/mmath/rational.nim b/src/mmath/rational.nim
index fd4856a..bfc01da 100644
--- a/src/mmath/rational.nim
+++ b/src/mmath/rational.nim
@@ -1,3 +1,7 @@
+import constant
+
+export constant
+
 proc gcd*[T](a : T, b : T) : T =
     var n1 = a
     var n2 = b 
@@ -30,38 +34,6 @@ proc simplify*[T](self : var Rational[T]) : void =
 proc newRational*[T](num : T) : Rational[T] = Rational[T](num: num, den: T(1))
 proc newRational*[T](num : T, den: T) : Rational[T] = Rational[T](num: num, den: den)
 
-proc one*[T : int64](_: type[T]) : T = 1.T
-
-proc zero*[T : int64](_: type[T]) : T = 0.T
-
-proc one*[T : uint64](_: type[T]) : T = 1.T
-
-proc zero*[T : uint64](_: type[T]) : T = 0.T
-
-proc one*[T : int](_: type[T]) : T = 1.T
-
-proc zero*[T : int](_: type[T]) : T = 0.T
-
-proc one*[T : uint](_: type[T]) : T = 1.T
-
-proc zero*[T : uint](_: type[T]) : T = 0.T
-
-proc one*[T : int16](_: type[T]) : T = 1.T
-
-proc zero*[T : int16](_: type[T]) : T = 0.T
-
-proc one*[T : uint16](_: type[T]) : T = 1.T
-
-proc zero*[T : uint16](_: type[T]) : T = 0.T
-
-proc one*[T : int8](_: type[T]) : T = 1.T
-
-proc zero*[T : int8](_: type[T]) : T = 0.T
-
-proc one*[T : uint8](_: type[T]) : T = 1.T
-
-proc zero*[T : uint8](_: type[T]) : T = 0.T
-
 proc zero*[T](_: type[Rational[T]]): Rational[T] = newRational(T.zero, T.one)
 
 proc one*[T](_: type[Rational[T]]): Rational[T] = newRational(T.one, T.one)
diff --git a/tests/test_bigint.nim b/tests/test_bigint.nim
new file mode 100644
index 0000000..7c83466
--- /dev/null
+++ b/tests/test_bigint.nim
@@ -0,0 +1,63 @@
+import mmath/bigint
+import unittest
+import random
+from strutils import parseBiggestUInt
+
+suite "Nim arbitrary precision integers (powered by GMP)":
+
+    let str = "2347822319"
+    test "parse " & str:
+        let str = "2347822319"
+        let bi = BigInt.fromString(str, 10)
+        let ul : BiggestUInt = parseBiggestUInt(str)
+        check newBigInt(ul.int64) == bi
+
+    var rng = initRand(101325)
+
+    for i in 0..5:
+        let n1 = rng.rand(-1000..1000).int64
+        let n2 = rng.rand(-1000..1000).int64
+        let bi1 = BigInt.of(n1)
+        let bi2 = BigInt.of(n2)
+
+        test $n1 & " + " & $n2:
+            check BigInt.of(n1 + n2) == bi1 + bi2
+
+        test $n1 & " - " & $n2:
+            check BigInt.of(n1 - n2) == bi1 - bi2
+
+        test $n1 & " * " & $n2:
+            check BigInt.of(n1 * n2) == bi1 * bi2
+
+        test $n1 & " div " & $n2:
+            check BigInt.of(n1 div n2) == bi1 div bi2
+
+        test $n1 & " mod " & $n2:
+            check BigInt.of(n1 mod n2) == bi1 mod bi2
+        
+        test $n1 & " pow " & $3:
+            check BigInt.of(n1 * n1 * n1) == pow(bi1, 3)
+
+        test "abs(" & $n1 & ")":
+            check BigInt.of(n1.abs()) == bi1.abs() 
+
+        test "abs(" & $n2 & ")":
+            check BigInt.of(n2.abs()) == bi2.abs() 
+
+        test $n1 & " cmp " & $n2:
+            check cmp(n1, n2) == cmp(bi1, bi2)
+
+        test $n1 & " < " & $n2:
+            check (n1 < n2) == (bi1 < bi2)
+
+        test $n1 & " > " & $n2:
+            check (n1 > n2) == (bi1 > bi2)
+
+        test $n1 & " == " & $n1:
+            check bi1 == bi1
+
+        test $n2 & " == " & $n2:
+            check bi2 == bi2
+
+        test $n1 & " != " & $n2:
+            check bi1 != bi2
\ No newline at end of file
diff --git a/tests/test_hmatrix.nim b/tests/test_hmatrix.nim
index 3bd2066..f08f19a 100644
--- a/tests/test_hmatrix.nim
+++ b/tests/test_hmatrix.nim
@@ -78,7 +78,7 @@ suite "Nim linear algebra library":
         var mtx  = newHMatrix[float64](100, 100, arr)
         var lu = mtx.clone()
         let pivot = lu.lup()
-        var b = newHVector[float64](100)
+        var b = newHVector[float64](100, 0.0f)
         for i in 0...len(b):
             b[i] = float64(rng.rand(b.len))
 
diff --git a/tests/test_smatrix.nim b/tests/test_smatrix.nim
index 78ecdc2..d31129c 100644
--- a/tests/test_smatrix.nim
+++ b/tests/test_smatrix.nim
@@ -4,7 +4,7 @@ from mmath/smatrix import det, lu, lup, lu_det, lup, det, from_pivot, invert, id
     newSMatrix, SMatrix, clone, tril, triu, lu_solve, `$`, `*`, `-`, `+`, `-=`, `+=`, `==`, `*`, norm2, newSMatrixFromArray,
     gauss_jordan_high, gauss_jordan_low, transpose, squared_norm2
 from mmath/svector import buildSVector, `-`, abs, norm, Svector
-from mmath/pivot import SingularMatrixError
+from mmath/error import SingularMatrixError
 from mmath/rational import newRational, Rational, one, zero, abs, `>`, `<`, `==`, `*`, `+`, `-`, `/`, `/=`, `+=`, `sqrt`
 import unittest
 
@@ -116,3 +116,4 @@ suite "Nim linear algebra library":
             let mtx = newSMatrixFromArray[2, 5, int]([1,4,8,2,5,7,3,6,9,0])
             let xpose = newSMatrixFromArray[5, 2, int]([1,7,4,3,8,6,2,9,5,0])
             check(mtx.transpose() == xpose)
+