Data commit

Task/Lah-numbers/J/lah-numbers.j

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+NB. use:   k lah n
+lah=: ! :(!&<: * %&!~)&x:  NB. `%~' is shorter than `*inv'
+
+NB. wory_lah translates lah to algebraic English.
+Monad =: :[:  NB. permit only a y argument
+Dyad =: [: :  NB. require x and y arguments
+but_1st =: &
+decrement =: <: Monad
+
+NB. ! means either factorial or combinations (just as - means negate or subtract)
+factorial =: ! Monad
+combinations =: ! Dyad
+
+into =: *inv Dyad
+times =: *  Dyad
+extend_precision =: x: Monad
+wordy_lah =: ((combinations but_1st decrement) times (into but_1st factorial))but_1st extend_precision Dyad