Consider the following code:
* A←3 4⍴1 3 2 0 2 1 0 1 4 0 0 2 B←4 2⍴4 1 0 3 0 2 2 0 Q←{⍺/⍵} (A≠0) +.Q B* My reading (and implementation) of the ISO spec suggests the output should be the following: ┏━━━┓ ┃4 6┃ ┃6 4┃ ┃6 1┃ ┗━━━┛ However, in GNU APL I get this: ┏→━━━━━━┓ ↓┏⊖┓ ┏⊖┓┃ ┃┃0┃ ┃0┃┃ ┃┗━┛ ┗━┛┃ ┃┏⊖┓ ┏⊖┓┃ ┃┃0┃ ┃0┃┃ ┃┗━┛ ┗━┛┃ ┃┏⊖┓ ┏⊖┓┃ ┃┃0┃ ┃0┃┃ ┃┗━┛ ┗━┛┃ ┗∊━━━━━━┛ Which one is correct? Regards, Elias