diff --git a/contracts/SafeMath.sol b/contracts/SafeMath.sol
index 92d2f45..82e3c0a 100644
--- a/contracts/SafeMath.sol
+++ b/contracts/SafeMath.sol
@@ -1,30 +1,6 @@
 pragma solidity ^0.7.0;
 
-// From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol
-// Subject to the MIT license.
-
-/**
- * @dev Wrappers over Solidity's arithmetic operations with added overflow
- * checks.
- *
- * Arithmetic operations in Solidity wrap on overflow. This can easily result
- * in bugs, because programmers usually assume that an overflow raises an
- * error, which is the standard behavior in high level programming languages.
- * `SafeMath` restores this intuition by reverting the transaction when an
- * operation overflows.
- *
- * Using this library instead of the unchecked operations eliminates an entire
- * class of bugs, so it's recommended to use it always.
- */
 library SafeMath {
-    /**
-     * @dev Returns the addition of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `+` operator.
-     *
-     * Requirements:
-     * - Addition cannot overflow.
-     */
     function add(uint256 a, uint256 b) internal pure returns (uint256) {
         uint256 c = a + b;
         require(c >= a, "SafeMath: addition overflow");
@@ -32,14 +8,6 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the addition of two unsigned integers, reverting with custom message on overflow.
-     *
-     * Counterpart to Solidity's `+` operator.
-     *
-     * Requirements:
-     * - Addition cannot overflow.
-     */
     function add(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
         uint256 c = a + b;
         require(c >= a, errorMessage);
@@ -47,26 +15,10 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative).
-     *
-     * Counterpart to Solidity's `-` operator.
-     *
-     * Requirements:
-     * - Subtraction cannot underflow.
-     */
     function sub(uint256 a, uint256 b) internal pure returns (uint256) {
         return sub(a, b, "SafeMath: subtraction underflow");
     }
 
-    /**
-     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative).
-     *
-     * Counterpart to Solidity's `-` operator.
-     *
-     * Requirements:
-     * - Subtraction cannot underflow.
-     */
     function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
         require(b <= a, errorMessage);
         uint256 c = a - b;
@@ -74,18 +26,7 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `*` operator.
-     *
-     * Requirements:
-     * - Multiplication cannot overflow.
-     */
     function mul(uint256 a, uint256 b) internal pure returns (uint256) {
-        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-        // benefit is lost if 'b' is also tested.
-        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
         if (a == 0) {
             return 0;
         }
@@ -96,18 +37,7 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `*` operator.
-     *
-     * Requirements:
-     * - Multiplication cannot overflow.
-     */
     function mul(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-        // benefit is lost if 'b' is also tested.
-        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
         if (a == 0) {
             return 0;
         }
@@ -118,32 +48,10 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the integer division of two unsigned integers.
-     * Reverts on division by zero. The result is rounded towards zero.
-     *
-     * Counterpart to Solidity's `/` operator. Note: this function uses a
-     * `revert` opcode (which leaves remaining gas untouched) while Solidity
-     * uses an invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
     function div(uint256 a, uint256 b) internal pure returns (uint256) {
         return div(a, b, "SafeMath: division by zero");
     }
 
-    /**
-     * @dev Returns the integer division of two unsigned integers.
-     * Reverts with custom message on division by zero. The result is rounded towards zero.
-     *
-     * Counterpart to Solidity's `/` operator. Note: this function uses a
-     * `revert` opcode (which leaves remaining gas untouched) while Solidity
-     * uses an invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
     function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
         // Solidity only automatically asserts when dividing by 0
         require(b > 0, errorMessage);
@@ -153,32 +61,10 @@ library SafeMath {
         return c;
     }
 
-    /**
-     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
-     * Reverts when dividing by zero.
-     *
-     * Counterpart to Solidity's `%` operator. This function uses a `revert`
-     * opcode (which leaves remaining gas untouched) while Solidity uses an
-     * invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
     function mod(uint256 a, uint256 b) internal pure returns (uint256) {
         return mod(a, b, "SafeMath: modulo by zero");
     }
 
-    /**
-     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
-     * Reverts with custom message when dividing by zero.
-     *
-     * Counterpart to Solidity's `%` operator. This function uses a `revert`
-     * opcode (which leaves remaining gas untouched) while Solidity uses an
-     * invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
     function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
         require(b != 0, errorMessage);
         return a % b;