====== Description ======
The if node selects a value or path based on the value of its first child-node.  The mode of operation is dependent on how many child-nodes the if node has. In all cases it is the value of the first (leftmost) node that controls the evaluation. 

^  child-node count  ^  returns  ^
|  1  |  0 or 1  |
|  2  |  0 or value<sub>2</sub>  |
|  3  |  value<sub>2</sub> or value<sub>3</sub>  |
|  4  |  value<sub>2</sub> or value<sub>3</sub> or value<sub>4</sub>  |

====== Constraints ======
  * Minimum number of child-nodes: 1
  * Maximum number of child-nodes: 4

====== Calculus ======

===== General =====
The first (leftmost) child-node is evaluated and compared to the child-node's weight((Weight is a node property that has meaning in only some situations.  By default its value is 1, but can be changed to any numeric value.)) to give a meta result.  This meta result then determines how the if node will act.  (see below)

^  value<sub>1</sub>  ^  meta result  ^
|  ''>''= weight<sub>1</sub>  |  true  |
|  ''<'' weight<sub>1</sub> AND ''>'' -weight<sub>1</sub>  |  undetermined  |
|  ''<''= -weight<sub>1</sub>  |  false  |
|  ERROR  |  ERROR  |

===== 1 child-node =====

^  value<sub>1</sub>  ^  meta result  ^  returns  ^
|  ''>''= weight<sub>1</sub>  |  true  |  1  |
|  ''<'' weight<sub>1</sub> AND ''>'' -weight<sub>1</sub>  |  undetermined  |  0  |
|  ''<''= -weight<sub>1</sub>  |  false  |  0  |
|  ERROR  |  ERROR  |  ERROR  |

===== 2 child-nodes =====

^  value<sub>1</sub>  ^  meta result  ^  returns  ^
|  ''>''= weight<sub>1</sub>  |  true  |  value<sub>2</sub>  |
|  ''<'' weight<sub>1</sub> AND ''>'' -weight<sub>1</sub>  |  undetermined  |  0  |
|  ''<''= -weight<sub>1</sub>  |  false  |  0  |
|  ERROR  |  ERROR  |  ERROR  |

===== 3 child-nodes =====

^  value<sub>1</sub>  ^  meta result  ^  returns  ^
|  ''>''= weight<sub>1</sub>  |  true  |  value<sub>2</sub>  |
|  ''<'' weight<sub>1</sub> AND ''>'' -weight<sub>1</sub>  |  undetermined  |  value<sub>3</sub>  |
|  ''<''= -weight<sub>1</sub>  |  false  |  value<sub>3</sub>  |
|  ERROR  |  ERROR  |  ERROR  |

===== 4 child-nodes =====

^  value<sub>1</sub>  ^  meta result  ^  returns  ^
|  ''>''= weight<sub>1</sub>  |  true  |  value<sub>2</sub>  |
|  ''<'' weight<sub>1</sub> AND ''>'' -weight<sub>1</sub>  |  undetermined  |  value<sub>3</sub>  |
|  ''<''= -weight<sub>1</sub>  |  false  |  value<sub>4</sub>  |
|  ERROR  |  ERROR  |  ERROR  |