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Introduction

NeurOn-Line provides you with Action blocks, which let you create loops, evaluate conditions, perform actions on other blocks, and execute rules.

You can find the Action Utilities under the Action & Other submenu of the Palettes menu:

You connect Action blocks together with Control Paths, which carry control signals. A block receives a control signal, performs its action, passes the control signal to the next block, and so on. A control signal does not have a value, but it makes sure that an action block is evaluated only after the previous one is done.

Unlike other blocks, an Action block's paths are on the top and bottom: the input path is on top and the output path is on the bottom, as in the figure below.

Some Action blocks also have an Action Link, which you connect to another NeurOn-Line block. It is shown in the figure above. When the Action block is evaluated, it performs its action on any block connected to its Action Link. For example, the Block Erase erases the data stored in the block connected to its Action Link.

Looping

These blocks let you create loops:

The Control Path Loop block lets you execute a loop for a specified number of times or until a specified condition is met.
The Control Path Circuit Breaker block lets NeurOn-Line know that a loop in your diagram is intentional. It is fully described in "Circuit Breakers".

Stopping Paths

These blocks let you stop the flow of data:

The N-to-1 Sieve block discards a specified number of signals before passing one.
The Control Inhibit block discards an incoming control signal if an inference input has a given value.

Outputting Data

These blocks let you pass an inference value or a count of control signals:

The Control Counter block passes on a data path the number of times it received a control signal. It also passes the control signal on an output control path.
The Inference Output block chooses which inference value to pass depending on which of its three input control paths it receives a signal on.

Branching

The Control Switch block lets an inference path choose on which path to send a control signal.

Performing Actions on Blocks

These blocks perform actions on other blocks. Most of these actions are similar to the menu choices available in a block's menu. Notice that there can be some small but important differences in how these blocks and the menu choices operate.

The Reset block resets a block.
The Evaluate block forces a block to evaluate.
The Clear block erases the data a block has stored.
The Make Permanent block makes permanent the data that a block has stored.
The Restore Permanent Values block restores to a block the data that you have previously made permanent.
The Attribute Transfer block transfers attribute values from one block to another.

Invoking a Rule

The Rule Action block can invoke a G2 rule you have written when it receives a control signal.

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Copyright © 1996, Gensym Corporation, Inc.