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## choice

Basis Function Combinator

Use a Boolean value to select one of two items. :

    A B false choice
    ----------------------
    A


    A B true choice
    ---------------------
      B

Currently Python semantics are used to evaluate the \"truthiness\" of
the Boolean value (so empty string, zero, etc. are counted as false,
etc.)

Gentzen diagram.

### Definition

if not basis.

### Derivation

if not basis.

### Source

if basis

### Discussion

Lorem ipsum.

### Crosslinks

Lorem ipsum.