Help System (web edition)

'if' statement:
Words and numbers in the tutstack are compared to each other and to constants
both as numbers and as strings by 'if' statements which are written
on edit lines having a '-' in the control column.
In string comparisons, the relational symbol must be given in inverted
commas.

The general form is
 - if <condition> then goto <label> 
or
 - if <condition> then load <another_sucro> 

where <condition> is a relation between tutstack words and constants.
Also an augmented form with an 'else' clause is available.

Examples:
 - if W1 '=' Tue then goto Tuesday
      If W1 contains string "Tue", sucro will continue from label 'Tuesday'.

 - if W2 < W3 then load EX1 else goto End
      If number in W2 is less than number in W3, call another sucro EX1
      else go to label 'End'.

 - if Wstr '=' {} then goto A
 - if Wstr '<>' {sp} then goto B
      If Wstr is empty, goto 'A'. If Wstr is not a space character,
      goto 'B'.

Permitted relational symbols are =, <, <=, >, >=, and <> .

In SURVO MM, numerical conditions in if statements of sucros can be
more general:
Example:

  / def Wheight=W1 Wlength=W2
  ...
  - if Wheight > 2*Wlength then goto A
  - if Wheight*Wlength = 4000 then goto B
  - if 100/Wlength > 0.7 then goto C else goto D
  ...

Thus on both sides of the condition, sums, differences, products,
and ratios of two operands may appear.

   S = More information on conditional statements 
   C = Code words and statements in sucros