1> L = [{a, 1}. {b,2}, {c, 3}, {d, 4}].

proplists:get_value(a, L).
proplists:get_value(b, L).
...
proplists:get_valus(d, L).

[{a, 1}. {b,2}, {c, 3}, {d, 4}] = L.

[{a, A}, {b, B}, {c, C}, {d, D}] = L,

[A, B, C, D] = [ proplists:get_value(X, L) || X <- [a,b,c,d] ],

A = proplists:get_value(a, L),
B = proplists:get_value(b, L),
C = proplists:get_value(c, L),
D = proplists:get_value(d, L),

[A, B, C, D] = [ V || Key <- [a,b,c,d], {K, V} <- L, K =:= Key ],